PROSPECTUS SUPPLEMENT
(To Prospectus dated July 18, 2008)

     This prospectus supplement relates to the issuance and sale of up to $30,000,000 of our common stock, par value $0.01 per share, from time to time through our sales agent, Cantor Fitzgerald & Co. These sales, if any, will be made pursuant to the terms of a sales agreement between us and the sales agent.

     Our common stock trades on the NASDAQ Global Market under the symbol “STEM.” Sales of shares of our common stock under this prospectus supplement, if any, may be made by any method permitted by law deemed to be an “at the market” offering as defined in Rule 415 under the Securities Act of 1933, as amended (the “Securities Act”), which includes sales made directly on the NASDAQ Global Market, the existing trading market for our common stock, or sales made to or through a market maker other than on an exchange. With our express written consent, the sales agent may also sell shares of our common stock in privately negotiated transactions. The sales agent will make all sales on a best efforts basis using commercially reasonable efforts consistent with its normal trading and sales practices, on terms mutually agreed upon by the sales agent and us. On June 5, 2009, the last reported sales price of our common stock on the NASDAQ Global Market was $1.75 per share.

     We will pay as compensation to the sales agent a fee of 3.0% of the gross proceeds of any sales of common stock sold pursuant to the sales agreement.

     In connection with the sale of common stock on our behalf, the sales agent may be deemed to be an “underwriter” within the meaning of the Securities Act, and the compensation of the sales agent may be deemed to be underwriting commissions or discounts. We have agreed to indemnify the sales agent and its controlling persons against certain liabilities, including liabilities under the Securities Act. If we are unable to provide this indemnification, we will contribute to payments the placement agent and its controlling persons may be required to make in respect of those liabilities.

     Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense.

     The date of this prospectus supplement is June 8, 2009.

PROSPECTUS

$100,000,000

STEMCELLS, INC.

Common Stock
Preferred Stock
Warrants
Debt Securities

     We may offer to the public, from time to time, in one or more series or issuances:

	•		shares of our common stock;
	•		shares of our preferred stock;
	•		warrants to purchase shares of our common stock, preferred stock and/or debt securities; or
	•		debt securities consisting of debentures, notes or other evidences of indebtedness.

     This prospectus provides a general description of the securities we may offer. Each time we sell securities, we will provide specific terms of the securities offered in a supplement to this prospectus. The prospectus supplement may also add, update or change information contained in this prospectus. You should read this prospectus and the applicable prospectus supplement carefully before you invest in any securities. This prospectus may not be used to consummate a sale of securities unless accompanied by an applicable prospectus supplement. You should read both this prospectus and any prospectus supplement together with additional information described under the heading “Where You Can Find More Information” before you make your investment decision.

     We will sell these securities directly to our stockholders or to purchasers or through agents on our behalf or through underwriters or dealers as designated from time to time. If any agents or underwriters are involved in the sale of any of these securities, the applicable prospectus supplement will provide the names of the agents or underwriters and any applicable fees, commissions or discounts.

     Our common stock is traded on the Nasdaq Global Market under the symbol “STEM.” On June 11, 2008, the closing price of our common stock was $1.37 per share.

     Investing in our securities involves risks. See “Risk Factors” on page 3.

     

     Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

     

The date of this prospectus is July 18, 2008

TABLE OF CONTENTS

		Page
About this Prospectus			1
About StemCells, Inc.			2
Risk Factors			3
Note Regarding Forward-Looking Statements			3
Use of Proceeds			4
Ratio of Earnings to Fixed Charges			4
Plan of Distribution			5
Description of Common Stock			7
Description of Preferred Stock			7
Description of Warrants			8
Description of Debt Securities			9
Where You Can Find More Information			16
Incorporation of Certain Documents by Reference			16
Legal Matters			17
Experts			17

     You should rely only on the information contained in this prospectus. We have not authorized anyone to give you information different from that contained in this prospectus. We are not making an offer to sell these securities in any jurisdiction where the offer is not permitted. The information contained in this prospectus is accurate only as of the date on the front cover of this prospectus, regardless of when this prospectus is delivered or when any sale of our securities occurs. Our business, financial condition, results of operations and prospects may have changed since that date.

ABOUT THIS PROSPECTUS

     This prospectus is a part of a registration statement that we filed with the Securities and Exchange Commission, or the SEC, using a “shelf” registration process. Under this shelf registration process, we may offer to sell any combination of the securities described in this prospectus in one or more offerings up to a total dollar amount of $100,000,000. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities under this shelf registration, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement may also add, update or change information contained in this prospectus. You should read both this prospectus and any prospectus supplement, including all documents incorporated herein or therein by reference, together with additional information described under “Where You Can Find More Information.”

     We have not authorized any dealer, salesman or other person to give any information or to make any representation other than those contained or incorporated by reference in this prospectus and any accompanying prospectus supplement. You must not rely upon any information or representation not contained or incorporated by reference in this prospectus or an accompanying prospectus supplement. This prospectus and the accompanying prospectus supplement, if any, do not constitute an offer to sell or the solicitation of an offer to buy any securities other than the registered securities to which they relate, nor do this prospectus and the accompanying prospectus supplement constitute an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make such offer or solicitation in such jurisdiction. You should not assume that the information contained in this prospectus and the accompanying prospectus supplement, if any, is accurate on any date subsequent to the date set forth on the front of the document or that any information we have incorporated by reference is correct on any date subsequent to the date of the document incorporated by reference, even though this prospectus and any accompanying prospectus supplement is delivered or securities are sold on a later date.

ABOUT STEMCELLS, INC.

     StemCells, Inc. is engaged in the discovery and development of cell-based therapeutics to treat damage to, or degeneration of, major organ systems. Our aim is to restore or support organ function, improve patients’ lives and reduce the substantial health care costs associated with these diseases and disorders by identifying and developing stem and progenitor cells as potential therapeutic agents. We currently have product development programs for two cell types: the human neural stem cell and human liver engrafting cells. In our CNS Program, we are conducting a Phase I clinical trial to evaluate the safety and preliminary efficacy of our HuCNS-SC^® product candidate (purified human neural stem cells) as a treatment for infantile and late infantile neuronal ceroid lipofuscinosis (NCL), two forms of a group of disorders often referred to as Batten disease. We have completed enrollment and dosing in this six-patient trial and expect it to be completed in early 2009. In addition, we are conducting preclinical work for spinal cord injury, myelin disorders and retinal disorders. In our Liver Program, we are in preclinical development with, and are continuing to improve processes to isolate and purify, our human liver engrafting cells (hLEC).

     Many degenerative diseases are caused by the loss of normal cellular function in a particular organ. When cells are damaged or destroyed, they no longer produce, metabolize or accurately regulate substances, such as sugars, amino acids, neurotransmitters, and hormones, which are essential to life. Although traditional pharmaceuticals and genetically engineered biologics may have some utility in addressing a degenerative condition, there is no technology existing today that can deliver these essential substances precisely to the sites of action, under the appropriate physiological regulation, in the appropriate quantity, or for the duration required to cure the degenerative condition. Cells, however, can do all this naturally. Thus, transplantation of stem or progenitor cells may prevent the loss of, or even generate new, functional cells and potentially maintain or restore organ function and the patient’s health.

     We believe that, if successfully developed, our cell technologies will create the basis for therapies that would address a number of conditions with significant unmet medical needs. Many neurodegenerative diseases involve the failure of an organ that cannot be transplanted, i.e., the brain or spinal cord. Many liver diseases, such as hepatitis, can be addressed by a liver transplant, but transplantable livers are in very limited supply. We estimate that degenerative conditions of the central nervous system (CNS) and the liver together affect more than 35 million people in the United States and account for nearly $200 billion annually in health care costs.¹

     Our principal executive offices are located at StemCells, Inc., 3155 Porter Drive, Palo Alto, CA 94304 and our phone number is (650) 475-3100.

RISK FACTORS

     You should consider the “Risk Factors” included under Part I-Item 1A. of our most recent Annual Report on Form 10-K, which is incorporated by reference in this prospectus. The risks and uncertainties we describe are not the only ones facing us. Additional risks not presently known to us, or that we currently deem immaterial, may also impair our business operations. If any of these risks were to occur, our business, financial condition, and results of operations could be severely harmed. This could cause the trading price of our common stock to decline, and you could lose all or part of your investment.

FORWARD-LOOKING STATEMENTS

     This prospectus and the documents incorporated in this prospectus by reference may contain “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). These statements may be identified by the use of forward-looking words or phrases such as “anticipate,” “believe,” “could,” “expect,” “intend,” “look forward,” “may,” “planned,” “potential,” “should,” “will,” and “would.” These forward-looking statements reflect our current expectations and are based upon currently available data. The Private Securities Litigation Reform Act of 1995 provides a “safe harbor” for such forward-looking statements. In order to comply with the terms of the safe harbor, we note that a variety of factors could cause actual results and experience to differ materially from the anticipated results or other expectations expressed in the forward-looking statements.

     Such statements include, without limitation, all statements as to expectation or belief and statements as to our future results of operations; the progress of our research, product development and clinical programs; the need for, and timing of, additional capital and capital expenditures; partnering prospects; costs of manufacture of products; the protection of, and the need for, additional intellectual property rights; effects of regulations; the need for additional facilities; and potential market opportunities. Our actual results may vary materially from those contained in such forward-looking statements because of risks to which we are subject, including uncertainty as to whether the U.S. Food and Drug Administration (FDA) or other regulatory authorities will permit us to proceed with clinical testing of proposed products despite the novel and unproven nature of our technologies; the risk that our initial clinical trial and any other clinical trials or studies could be substantially delayed beyond their expected dates or cause us to incur substantial unanticipated costs; uncertainties in our ability to obtain the capital resources needed to continue our current research and development operations and to conduct the research, preclinical development and clinical trials necessary for regulatory approvals; the uncertainty regarding our ability to obtain a corporate partner or partners, if needed, to support the development and commercialization of our potential cell-based therapeutics products; the uncertainty regarding the outcome of our Phase I clinical trial in NCL and any other clinical trials or studies we may conduct in the future; the uncertainty regarding the validity and enforceability of our issued patents; the uncertainty whether any products that may be generated in our cell-based therapeutics programs will prove clinically safe and effective; the uncertainty whether we will achieve revenue from product sales or become profitable; uncertainties regarding our obligations with respect to our former encapsulated cell therapy facilities in Rhode Island; obsolescence of our technologies; competition from third parties; intellectual property rights of third parties; litigation risks; and other risks to which we are subject. All forward-looking statements attributable to us or to persons acting on our behalf are expressly qualified in their entirety by the cautionary statements and risk factors set forth in “Risk Factors” in this prospectus.

     The forward-looking statements included in this prospectus represent our estimates as of the date of this prospectus. We specifically disclaim any obligation to update these forward-looking statements in the future. These forward-looking statements should not be relied upon as representing our estimates or views as of any date subsequent to the date of this prospectus.

USE OF PROCEEDS

     Except as otherwise provided in the applicable prospectus supplement, we intend to use the net proceeds from the sale of the securities covered by this prospectus for general corporate purposes, which may include working capital, capital expenditures, research and development expenditures, clinical trial expenditures, acquisitions of new technologies or businesses, and investments. Additional information on the use of net proceeds from the sale of securities covered by this prospectus may be set forth in the prospectus supplement relating to the specific offering.

RATIO OF EARNINGS TO FIXED CHARGES

     Our earnings are inadequate to cover fixed charges. The following table sets forth the dollar amount of the coverage. We have not included a ratio of earnings to combined fixed charges and preferred stock dividends because we do not have any preferred stock outstanding.

																						Three Months
																						Ended
		Year Ended December 31,																				March 31,
		2003				2004				2005				2006				2007				2008
										(in thousands)
Ratio of earnings to fixed charges (1)			—				—				—				—				—				—
Deficiency of earnings available to cover fixed charges		$	(14,425	)		$	(15,330	)		$	(11,738	)		$	(18,948	)		$	(25,023	)		$	(6,545	)

PLAN OF DISTRIBUTION

          We may sell securities in any of the ways described below or in any combination of these:

	•		to or through underwriters or dealers;
	•		through one or more agents; or
	•		directly to purchasers or to a single purchaser.

          The distribution of the securities may be effected from time to time in one or more transactions:

	•		at a fixed price, or prices, which may be changed from time to time;
	•		at market prices prevailing at the time of sale;
	•		at prices related to such prevailing market prices; or
	•		at negotiated prices.

          Each prospectus supplement will describe the method of distribution of the securities and any applicable restrictions.

          The prospectus supplement with respect to the securities of a particular series will describe the terms of the offering of the securities, including the following:

	•		the name or names of any underwriters, dealers or agents and the amounts of securities underwritten or purchased by each of them;
	•		the initial public offering price of the securities and the proceeds to us and any discounts, commissions or concessions allowed or reallowed or paid to dealers; and
	•		any securities exchanges on which the securities may be listed.

          Any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers may be changed from time to time.

          Only the agents or underwriters named in each prospectus supplement are agents or underwriters in connection with the securities being offered thereby.

          We may authorize underwriters, dealers or other persons acting as our agents to solicit offers by certain institutions to purchase securities from us pursuant to delayed delivery contracts providing for payment and delivery on the date stated in each applicable prospectus supplement. Each contract will be for an amount not less than, and the aggregate amount of securities sold pursuant to such contracts shall not be less nor more than, the respective amounts stated in each applicable prospectus supplement. Institutions with whom the contracts, when authorized, may be made include commercial and savings banks, insurance companies, pension funds, investment companies, educational and charitable institutions and other institutions, but shall in all cases be subject to our approval. Delayed delivery contracts will be subject only to those conditions set forth in each applicable prospectus supplement, and each prospectus supplement will set forth any commissions we pay for solicitation of these contracts.

          Agents, underwriters and other third parties described above may be entitled to indemnification by us against certain civil liabilities, including liabilities under the Securities Act of 1933, or to contribution with respect to payments which the agents or underwriters may be required to make in respect thereof. Agents, underwriters and such other third parties may be customers of, engage in transactions with, or perform services for us in the ordinary course of business.

          One or more firms, referred to as “remarketing firms,” may also offer or sell the securities, if a prospectus supplement so indicates, in connection with a remarketing arrangement upon their purchase. Remarketing firms will act as principals for their own accounts or as our agents. These remarketing firms will offer or sell the securities in accordance with the terms of the securities. Each prospectus supplement will identify any remarketing firm and the terms of its agreement, if any, with us and will describe the remarketing firm and the terms of its agreement, if any, with us and will describe the remarketing firm’s compensation. Remarketing firms may be deemed to be underwriters in connection with the securities they remarket. Remarketing firms may be entitled under agreements that may be entered into with us to indemnification by us against certain civil liabilities, including liabilities under the Securities Act of 1933, and may be customers of, engage in transactions with or perform services for us in the ordinary course of business.

          Certain underwriters may use this prospectus and any accompanying prospectus supplement for offers and sales related to market-making transactions in the securities. These underwriters may act as principal or agent in these transactions, and the sales will be made at prices related to prevailing market prices at the time of sale.

          The securities may be new issues of securities and may have no established trading market. The securities may or may not be listed on a national securities exchange. Underwriters may make a market in these securities, but will not be obligated to do so and may discontinue any market making at any time without notice. We can make no assurance as to the liquidity of, or the existence of trading markets for, any of our securities.

          Certain persons participating in this offering may engage in overallotment, stabilizing transactions, short covering transactions and penalty bids in accordance with rules and regulations under the Exchange Act. Overallotment involves sales in excess of the offering size, which create a short position. Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum. Short covering transactions involve purchases of the securities in the open market after the distribution is completed to cover short positions. Penalty bids permit the underwriters to reclaim a selling concession from a dealer when the securities originally sold by the dealer are purchased in a covering transaction to cover short positions. Those activities may cause the price of the securities to be higher than it would otherwise be. If commenced, the underwriters may discontinue any of the activities at any time.

DESCRIPTION OF COMMON STOCK

     We are authorized to issue 125,000,000 shares of common stock. As of June 1, 2008, we had 80,810,302 shares of common stock outstanding.

     The following summary of certain provisions of our common stock does not purport to be complete. You should refer to our restated certificate of incorporation and our amended and restated by-laws, both of which are on file with the SEC as exhibits to previous SEC filings. The summary below is also qualified by provisions of applicable law.

General

     Holders of common stock are entitled to one vote per share on matters on which our stockholders vote. There are no cumulative voting rights. Holders of common stock are entitled to receive dividends, if declared by our board of directors, out of funds that we may legally use to pay dividends. If we liquidate or dissolve, holders of common stock are entitled to share ratably in our assets once our debts and any liquidation preference owed to any then-outstanding preferred stockholders are paid. Our certificate of incorporation does not provide the common stock with any redemption, conversion or preemptive rights. All shares of common stock that are outstanding as of the date of this prospectus and, upon issuance and sale, all shares we are offering by this prospectus, will be fully-paid and nonassessable.

Transfer Agent and Registrar

     The transfer agent and registrar for our common stock is Computershare Trust Company, N.A.

Nasdaq Global Market

     Our common stock is listed for quotation on the Nasdaq Global Market under the symbol “STEM.”

DESCRIPTION OF PREFERRED STOCK

     We are authorized to issue 1,000,000 shares of undesignated preferred stock. As of June 1, 2008, no shares of our preferred stock were outstanding. The following summary of certain provisions of our preferred stock does not purport to be complete. You should refer to our restated certificate of incorporation and our amended and restated by-laws, both of which are on file with the SEC as exhibits to previous SEC filings. The summary below is also qualified by provisions of applicable law.

     Our board of directors may, without further action by our stockholders, from time to time, direct the issuance of shares of preferred stock in series and may, at the time of issuance, determine the rights, preferences and limitations of each series, including voting rights, dividend rights and redemption and liquidation preferences. Satisfaction of any dividend preferences of outstanding shares of preferred stock would reduce the amount of funds available for the payment of dividends on shares of our common stock. Holders of shares of preferred stock may be entitled to receive a preference payment in the event of any liquidation, dissolution or winding-up of our company before any payment is made to the holders of shares of our common stock. In some circumstances, the issuance of shares of preferred stock may render more difficult or tend to discourage a merger, tender offer or proxy contest, the assumption of control by a holder of a large block of our securities or the removal of incumbent management. Upon the affirmative vote of our board of directors, without stockholder approval, we may issue shares of preferred stock with voting and conversion rights which could adversely affect the holders of shares of our common stock.

     If we offer a specific series of preferred stock under this prospectus, we will describe the terms of the preferred stock in the prospectus supplement for such offering and will file a copy of the certificate establishing the terms of the preferred stock with the SEC. To the extent required, this description will include:

•

the title and stated value;

	•		the number of shares offered, the liquidation preference per share and the purchase price;
	•		the dividend rate(s), period(s) and/or payment date(s), or method(s) of calculation for such dividends;
	•		whether dividends will be cumulative or non-cumulative and, if cumulative, the date from which dividends will accumulate;
	•		the procedures for any auction and remarketing, if any;
	•		the provisions for a sinking fund, if any;
	•		the provisions for redemption, if applicable;
	•		any listing of the preferred stock on any securities exchange or market;
	•		whether the preferred stock will be convertible into our common stock, and, if applicable, the conversion price (or how it will be calculated) and conversion period;
	•		whether the preferred stock will be exchangeable into debt securities, and, if applicable, the exchange price (or how it will be calculated) and exchange period;
	•		voting rights, if any, of the preferred stock;
	•		a discussion of any material and/or special U.S. federal income tax considerations applicable to the preferred stock;
	•		the relative ranking and preferences of the preferred stock as to dividend rights and rights upon liquidation, dissolution or winding up of the affairs of StemCells, Inc.; and
	•		any material limitations on issuance of any class or series of preferred stock ranking senior to or on a parity with the series of preferred stock as to dividend rights and rights upon liquidation, dissolution or winding up of StemCells, Inc.

     The preferred stock offered by this prospectus, when issued, will not have, or be subject to, any preemptive or similar rights.

Transfer Agent and Registrar

     The transfer agent and registrar for any series or class of preferred stock will be set forth in each applicable prospectus supplement.

DESCRIPTION OF WARRANTS

     We may issue warrants to purchase shares of our common stock, preferred stock and/or debt securities in one or more series together with other securities or separately, as described in each applicable prospectus supplement. Below is a description of certain general terms and provisions of the warrants that we may offer. Particular terms of the warrants will be described in the applicable warrant agreements and the applicable prospectus supplement to the warrants.

     The applicable prospectus supplement will contain, where applicable, the following terms of, and other information relating to, the warrants:

	•		the specific designation and aggregate number of, and the price at which we will issue, the warrants;
	•		the currency or currency units in which the offering price, if any, and the exercise price are payable;
	•		the designation, amount and terms of the securities purchasable upon exercise of the warrants;
	•		if applicable, the exercise price for shares of our common stock and the number of shares of common stock to be received upon exercise of the warrants;
	•		if applicable, the exercise price for shares of our preferred stock, the number of shares of preferred stock to be received upon exercise, and a description of that series of our preferred stock;

	•		if applicable, the exercise price for our debt securities, the amount of debt securities to be received upon exercise, and a description of that series of debt securities;
	•		the date on which the right to exercise the warrants will begin and the date on which that right will expire or, if you may not continuously exercise the warrants throughout that period, the specific date or dates on which you may exercise the warrants;
	•		whether the warrants will be issued in fully registered form or bearer form, in definitive or global form or in any combination of these forms, although, in any case, the form of a warrant included in a unit will correspond to the form of the unit and of any security included in that unit;
	•		any applicable material U.S. federal income tax consequences;
	•		the identity of the warrant agent for the warrants and of any other depositaries, execution or paying agents, transfer agents, registrars or other agents;
	•		the proposed listing, if any, of the warrants or any securities purchasable upon exercise of the warrants on any securities exchange;
	•		if applicable, the date from and after which the warrants and the common stock, preferred stock and/or debt securities will be separately transferable;
	•		if applicable, the minimum or maximum amount of the warrants that may be exercised at any one time;
	•		information with respect to book-entry procedures, if any;
	•		the anti-dilution provisions of the warrants, if any;
	•		any redemption or call provisions;
	•		whether the warrants are to be sold separately or with other securities as parts of units; and
	•		any additional terms of the warrants, including terms, procedures and limitations relating to the exchange and exercise of the warrants.

Transfer Agent and Registrar

     The transfer agent and registrar for any warrants will be set forth in the applicable prospectus supplement.

DESCRIPTION OF DEBT SECURITIES

     We will issue the debt securities offered by this prospectus and any accompanying prospectus supplement under an indenture to be entered into between us and the trustee identified in the applicable prospectus supplement. The terms of the debt securities will include those stated in the indenture and those made part of the indenture by reference to the Trust Indenture Act of 1939, as in effect on the date of the indenture. We have filed a copy of the form of indenture as an exhibit to the registration statement in which this prospectus is included. The indenture will be subject to and governed by the terms of the Trust Indenture Act of 1939.

     We may offer under this prospectus up to an aggregate principal amount of $100,000,000 in debt securities; or if debt securities are issued at a discount, or in a foreign currency, foreign currency units or composite currency, the principal amount as may be sold for an initial public offering price of up to $100,000,000. Unless otherwise specified in the applicable prospectus supplement, the debt securities will represent direct, unsecured obligations of StemCells, Inc. and will rank equally with all of our other unsecured indebtedness.

     The following statements relating to the debt securities and the indenture are summaries, qualified in their entirety to the detailed provisions of the indenture.

General

     We may issue the debt securities in one or more series with the same or various maturities, at par, at a premium, or at a discount. We will describe the particular terms of each series of debt securities in a prospectus supplement relating to that series, which we will file with the SEC.

     The prospectus supplement will set forth, to the extent required, the following terms of the debt securities in respect of which the prospectus supplement is delivered:

	•		the title of the series;
	•		the aggregate principal amount;
	•		the issue price or prices, expressed as a percentage of the aggregate principal amount of the debt securities;
	•		any limit on the aggregate principal amount;
	•		the date or dates on which principal is payable;
	•		the interest rate or rates (which may be fixed or variable) or, if applicable, the method used to determine such rate or rates;
	•		the date or dates from which interest, if any, will be payable and any regular record date for the interest payable;
	•		the place or places where principal and, if applicable, premium and interest, is payable;
	•		the terms and conditions upon which we may, or the holders may require us to, redeem or repurchase the debt securities;
	•		the denominations in which such debt securities may be issuable, if other than denominations of $1,000 or any integral multiple of that number;
	•		whether the debt securities are to be issuable in the form of certificated debt securities (as described below) or global debt securities (as described below);
	•		the portion of principal amount that will be payable upon declaration of acceleration of the maturity date if other than the principal amount of the debt securities;
	•		the currency of denomination;
	•		the designation of the currency, currencies or currency units in which payment of principal and, if applicable, premium and interest, will be made;
	•		if payments of principal and, if applicable, premium or interest, on the debt securities are to be made in one or more currencies or currency units other than the currency of denomination, the manner in which the exchange rate with respect to such payments will be determined;
	•		if amounts of principal and, if applicable, premium and interest may be determined by reference to an index based on a currency or currencies or by reference to a commodity, commodity index, stock exchange index or financial index, then the manner in which such amounts will be determined;
	•		the provisions, if any, relating to any collateral provided for such debt securities;
	•		any addition to or change in the covenants and/or the acceleration provisions described in this prospectus or in the indenture;
	•		any events of default, if not otherwise described below under “Events of Default”;
	•		the terms and conditions, if any, for conversion into or exchange for shares of common stock or preferred stock;
	•		any depositaries, interest rate calculation agents, exchange rate calculation agents or other agents; and

•

the terms and conditions, if any, upon which the debt securities shall be subordinated in right of payment to other indebtedness of StemCells, Inc.

     We may issue discount debt securities that provide for an amount less than the stated principal amount to be due and payable upon acceleration of the maturity of such debt securities in accordance with the terms of the indenture. We may also issue debt securities in bearer form, with or without coupons. If we issue discount debt securities or debt securities in bearer form, we will describe material U.S. federal income tax considerations and other material special considerations which apply to these debt securities in the applicable prospectus supplement.

     We may issue debt securities denominated in or payable in a foreign currency or currencies or a foreign currency unit or units. If we do, we will describe the restrictions, elections, and general tax considerations relating to the debt securities and the foreign currency or currencies or foreign currency unit or units in the applicable prospectus supplement.

Exchange and/or Conversion Rights

     We may issue debt securities which can be exchanged for or converted into shares of common stock or preferred stock. If we do, we will describe the terms of exchange or conversion in the prospectus supplement relating to these debt securities.

Transfer and Exchange

     We may issue debt securities that will be represented by either:

	•		“book-entry securities,” which means that there will be one or more global securities registered in the name of a depositary or a nominee of a depositary; or
	•		“certificated securities,” which means that they will be represented by a certificate issued in definitive registered form.

     We will specify in the prospectus supplement applicable to a particular offering whether the debt securities offered will be book-entry or certificated securities.

Certificated Debt Securities

     If you hold certificated debt securities, you may transfer or exchange such debt securities at the trustee’s office or at the paying agent’s office or agency in accordance with the terms of the indenture. You will not be charged a service charge for any transfer or exchange of certificated debt securities but may be required to pay an amount sufficient to cover any tax or other governmental charge payable in connection with such transfer or exchange.

     You may effect the transfer of certificated debt securities and of the right to receive the principal of, premium, and/or interest, if any, on the certificated debt securities only by surrendering the certificate representing the certificated debt securities and having us or the trustee issue a new certificate to the new holder.

Global Securities

     If we decide to issue debt securities in the form of one or more global securities, then we will register the global securities in the name of the depositary for the global securities or the nominee of the depositary, and the global securities will be delivered by the trustee to the depositary for credit to the accounts of the holders of beneficial interests in the debt securities.

     The prospectus supplement will describe the specific terms of the depositary arrangement for debt securities of a series that are issued in global form. None of our company, the trustee, any payment agent or the security registrar will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in a global debt security or for maintaining, supervising or reviewing any records relating to these beneficial ownership interests.

No Protection in the Event of Change of Control

     The indenture does not have any covenants or other provisions providing for a put or increased interest or otherwise that would afford holders of debt securities additional protection in the event of a recapitalization transaction, a change of control of StemCells, Inc., or a highly leveraged transaction. If we offer any covenants or provisions of this type with respect to any debt securities covered by this prospectus, we will describe them in the applicable prospectus supplement.

Covenants

     Unless otherwise indicated in this prospectus or a prospectus supplement, the debt securities will not have the benefit of any covenants that limit or restrict our business or operations, the pledging of our assets or the incurrence by us of indebtedness. We will describe in the applicable prospectus supplement any material covenants in respect of a series of debt securities.

Consolidation, Merger and Sale of Assets

     We have agreed in the indenture that we will not consolidate with or merge into any other person or convey, transfer, sell or lease our properties and assets substantially as an entirety to any person, unless:

	•		the person formed by the consolidation or into or with which we are merged or the person to which our properties and assets are conveyed, transferred, sold or leased, is a corporation organized and existing under the laws of the U.S., any state or the District of Columbia or a corporation or comparable legal entity organized under the laws of a foreign jurisdiction and, if we are not the surviving person, the surviving person has expressly assumed all of our obligations, including the payment of the principal of and, premium, if any, and interest on the debt securities and the performance of the other covenants under the indenture; and
	•		immediately before and immediately after giving effect to the transaction, no event of default, and no event which, after notice or lapse of time or both, would become an event of default, has occurred and is continuing under the indenture.

Events of Default

     Unless otherwise specified in the applicable prospectus supplement, the following events will be events of default under the indenture with respect to debt securities of any series:

	•		we fail to pay any principal or premium, if any, when it becomes due;
	•		we fail to pay any interest within 30 days after it becomes due;
	•		we fail to observe or perform any other covenant in the debt securities or the indenture for 60 days after written notice specifying the failure from the trustee or the holders of not less than 25% in aggregate principal amount of the outstanding debt securities of that series; and
	•		certain events involving bankruptcy, insolvency or reorganization of StemCells, Inc. or any of our significant subsidiaries.

     The trustee may withhold notice to the holders of the debt securities of any series of any default, except in payment of principal of or premium, if any, or interest on the debt securities of a series, if the trustee considers it to be in the best interest of the holders of the debt securities of that series to do so.

     If an event of default (other than an event of default resulting from certain events of bankruptcy, insolvency or reorganization) occurs, and is continuing, then the trustee or the holders of not less than 25% in aggregate principal amount of the outstanding debt securities of any series may accelerate the maturity of the debt securities. If this happens, the entire principal amount, plus the premium, if any, of all the outstanding debt securities of the affected series plus accrued interest to the date of acceleration will be immediately due and payable. At any time after the acceleration, but before a judgment or decree based on such acceleration is obtained by the trustee, the holders of a

majority in aggregate principal amount of outstanding debt securities of such series may rescind and annul such acceleration if:

	•		all events of default (other than nonpayment of accelerated principal, premium or interest) have been cured or waived;
	•		all lawful interest on overdue interest and overdue principal has been paid; and
	•		the rescission would not conflict with any judgment or decree.

     In addition, if the acceleration occurs at any time when we have outstanding indebtedness which is senior to the debt securities, the payment of the principal amount of outstanding debt securities may be subordinated in right of payment to the prior payment of any amounts due under the senior indebtedness, in which case the holders of debt securities will be entitled to payment under the terms prescribed in the instruments evidencing the senior indebtedness and the indenture.

     If an event of default resulting from certain events of bankruptcy, insolvency or reorganization occurs, the principal, premium and interest amount with respect to all of the debt securities of any series will be due and payable immediately without any declaration or other act on the part of the trustee or the holders of the debt securities of that series.

     The holders of a majority in principal amount of the outstanding debt securities of a series will have the right to waive any existing default or compliance with any provision of the indenture or the debt securities of that series and to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, subject to certain limitations specified in the indenture.

     No holder of any debt security of a series will have any right to institute any proceeding with respect to the indenture or for any remedy under the indenture, unless:

	•		the holder gives to the trustee written notice of a continuing event of default;
	•		the holders of at least 25% in aggregate principal amount of the outstanding debt securities of the affected series make a written request and offer reasonable indemnity to the trustee to institute a proceeding as trustee;
	•		the trustee fails to institute a proceeding within 60 days after such request; and
	•		the holders of a majority in aggregate principal amount of the outstanding debt securities of the affected series do not give the trustee a direction inconsistent with such request during such 60-day period.

     These limitations do not, however, apply to a suit instituted for payment on debt securities of any series on or after the due dates expressed in the debt securities.

     We will periodically deliver certificates to the trustee regarding our compliance with our obligations under the indenture.

Modification and Waiver

     From time to time, we and the trustee may, without the consent of holders of the debt securities of one or more series, amend the indenture or the debt securities of one or more series, or supplement the indenture, for certain specified purposes, including:

	•		to provide that the surviving entity following a change of control of StemCells, Inc. permitted under the indenture will assume all of our obligations under the indenture and debt securities;
	•		to provide for certificated debt securities in addition to uncertificated debt securities;
	•		to comply with any requirements of the SEC under the Trust Indenture Act of 1939;

	•		to provide for the issuance of and establish the form and terms and conditions of debt securities of any series as permitted by the indenture;
	•		to cure any ambiguity, defect or inconsistency, or make any other change that does not materially and adversely affect the rights of any holder; and
	•		to appoint a successor trustee under the indenture with respect to one or more series.

     From time to time we and the trustee may, with the consent of holders of at least a majority in principal amount of an outstanding series of debt securities, amend or supplement the indenture or the debt securities of such series, or waive compliance in a particular instance by us with any provision of the indenture or such debt securities. We may not, however, without the consent of each holder affected by such action, modify or supplement the indenture or the debt securities or waive compliance with any provision of the indenture or the debt securities in order to:

	•		reduce the amount of debt securities whose holders must consent to an amendment, supplement, or waiver to the indenture or such debt security;
	•		reduce the rate of or change the time for payment of interest or reduce amount of or postpone the date for payment of sinking fund or analogous obligations;
	•		reduce the principal of or change the stated maturity of the debt securities;
	•		make any debt security payable in money other than that stated in the debt security;
	•		change the amount or time of any payment required or reduce the premium payable upon any redemption, or change the time before which no such redemption may be made;
	•		waive a default in the payment of the principal of, premium, if any, or interest on the debt securities or a redemption payment;
	•		waive a redemption payment with respect to any debt securities or change any provision with respect to redemption of debt securities; or
	•		take any other action otherwise prohibited by the indenture to be taken without the consent of each holder affected by the action.

Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

     The indenture permits us, at any time, to elect to discharge our obligations with respect to one or more series of debt securities by following certain procedures described in the indenture. These procedures will allow us either:

•

to defease and be discharged from any and all of our obligations with respect to any debt securities except for the following obligations (which discharge is referred to as “legal defeasance”):

                    (1) to register the transfer or exchange of such debt securities;

                    (2) to replace temporary or mutilated, destroyed, lost or stolen debt securities;

                    (3) to compensate and indemnify the trustee; or

                    (4) to maintain an office or agency in respect of the debt securities and to hold monies for payment in trust; or

•

to be released from our obligations with respect to the debt securities under certain covenants contained in the indenture, as well as any additional covenants which may be contained in the applicable supplemental indenture (which release is referred to as “covenant defeasance”).

     In order to exercise either defeasance option, we must deposit with the trustee or other qualifying trustee, in trust for that purpose:

•

money;

	•		U.S. Government Obligations (as described below) or Foreign Government Obligations (as described below) which through the scheduled payment of principal and interest in accordance with their terms will provide money; or
	•		a combination of money and/or U.S. Government Obligations and/or Foreign Government Obligations sufficient, in the written opinion of a nationally-recognized firm of independent accountants, to provide money;

which in each case specified above, provides a sufficient amount to pay the principal of, premium, if any, and interest, if any, on the debt securities of the series, on the scheduled due dates or on a selected date of redemption in accordance with the terms of the indenture.

     In addition, defeasance may be effected only if, among other things:

	•		in the case of either legal or covenant defeasance, we deliver to the trustee an opinion of counsel, as specified in the indenture, stating that as a result of the defeasance neither the trust nor the trustee will be required to register as an investment company under the Investment Company Act of 1940;
	•		in the case of legal defeasance, we deliver to the trustee an opinion of counsel stating that we have received from, or there has been published by, the Internal Revenue Service a ruling to the effect that, or there has been a change in any applicable federal income tax law with the effect that (and the opinion shall confirm that), the holders of outstanding debt securities will not recognize income, gain or loss for U.S. federal income tax purposes solely as a result of such legal defeasance and will be subject to U.S. federal income tax on the same amounts, in the same manner, including as a result of prepayment, and at the same times as would have been the case if legal defeasance had not occurred;
	•		in the case of covenant defeasance, we deliver to the trustee an opinion of counsel to the effect that the holders of the outstanding debt securities will not recognize income, gain or loss for U.S. federal income tax purposes as a result of covenant defeasance and will be subject to U.S. federal income tax on the same amounts, in the same manner and at the same times as would have been the case if covenant defeasance had not occurred; and
	•		certain other conditions described in the indenture are satisfied.

     If we fail to comply with our remaining obligations under the indenture and applicable supplemental indenture after a covenant defeasance of the indenture and applicable supplemental indenture, and the debt securities are declared due and payable because of the occurrence of any undefeased event of default, the amount of money and/or U.S. Government Obligations and/or Foreign Government Obligations on deposit with the trustee could be insufficient to pay amounts due under the debt securities of the affected series at the time of acceleration. We will, however, remain liable in respect of these payments.

     The term “U.S. Government Obligations” as used in the above discussion means securities which are direct obligations of or non-callable obligations guaranteed by the United States of America for the payment of which obligation or guarantee the full faith and credit of the United States of America is pledged.

     The term “Foreign Government Obligations” as used in the above discussion means, with respect to debt securities of any series that are denominated in a currency other than U.S. dollars (1) direct obligations of the government that issued or caused to be issued such currency for the payment of which obligations its full faith and credit is pledged or (2) obligations of a person controlled or supervised by or acting as an agent or instrumentality of such government the timely payment of which is unconditionally guaranteed as a full faith and credit obligation by that government, which in either case under clauses (1) or (2), are not callable or redeemable at the option of the issuer.

Regarding the Trustee

     We will identify the trustee with respect to any series of debt securities in the prospectus supplement relating to the applicable debt securities. You should note that if the trustee becomes a creditor of StemCells, Inc., the indenture and the Trust Indenture Act of 1939 limit the rights of the trustee to obtain payment of claims in certain cases, or to

realize on certain property received in respect of any such claim, as security or otherwise. The trustee and its affiliates may engage in, and will be permitted to continue to engage in, other transactions with us and our affiliates. If, however, the trustee acquires any “conflicting interest” within the meaning of the Trust Indenture Act of 1939, it must eliminate such conflict or resign.

     The holders of a majority in principal amount of the then outstanding debt securities of any series may direct the time, method and place of conducting any proceeding for exercising any remedy available to the trustee. If an event of default occurs and is continuing, the trustee, in the exercise of its rights and powers, must use the degree of care and skill of a prudent person in the conduct of his or her own affairs. Subject to that provision, the trustee will be under no obligation to exercise any of its rights or powers under the indenture at the request of any of the holders of the debt securities, unless they have offered to the trustee reasonable indemnity or security.

WHERE YOU CAN FIND MORE INFORMATION

     We have filed a registration statement on Form S-3 with the SEC for the stock we are offering by this prospectus. This prospectus does not include all of the information contained in the registration statement. You should refer to the registration statement and its exhibits for additional information.

     We are required to file annual and quarterly reports, special reports, proxy statements, and other information with the SEC. We make these documents publicly available, free of charge, on our website at www.stemcellsinc.com as soon as reasonably practicable after filing such documents with the SEC. You can read our SEC filings, including the registration statement, on the SEC’s website at http://www.sec.gov. You also may read and copy any document we file with the SEC at its public reference facility at:

Public Reference Room
100 F Street N.E.
Washington, DC 20549.

     Please call the SEC at 1-800-732-0330 for further information on the operation of the public reference facilities.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

     The SEC allows us to “incorporate by reference” into this prospectus the information we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus, and information in documents that we file later with the SEC will automatically update and supersede information in this prospectus. We incorporate by reference the documents listed below into this prospectus, and any future filings made by us with the SEC under Section 13(a), 13(c), 14 or 15(d) of the Exchange Act until we close this offering, including all filings made after the date of the initial registration statement and prior to the effectiveness of the registration statement. We hereby incorporate by reference the following documents:

	•		Our Annual Report on Form 10-K (as amended) for the year ended December 31, 2007 (File No. 000-19871);
	•		Our Quarterly Report on Form 10-Q for the quarter ended March 31, 2008 (File No. 000-19871);
	•		Our Current Reports on Form 8-K filed on March 5, 2008, March 21, 2008 and May 13, 2008 (File No. 000-19871);
	•		The description of our common stock contained in our registration statements on Form 8-A (File No. 000-19871) filed August 3, 1998, under the Exchange Act, including any amendment or report filed for the purpose of updating such description; and
	•		Our definitive Proxy Statement on Form DEF 14A filed on June 9, 2008 (File No. 000-19871).

     You may request a copy of these filings, at no cost, by writing or telephoning us at the following address:

StemCells, Inc.
3155 Porter Drive
Palo Alto, Ca 94304
Attention: Investor Relations
Phone: (650) 475-3100
email: irpr@stemcellsinc.com

          Copies of these filings are also available, without charge, on our Internet website at www.stemcellsinc.com as soon as reasonably practicable after they are filed electronically with the SEC. The information contained on our website is not a part of this prospectus.

LEGAL MATTERS

     The validity of the issuance of the securities offered hereby will be passed upon for us by Ropes & Gray LLP, Boston, Massachusetts. The validity of any securities will be passed upon for any underwriters or agents by counsel that we will name in the applicable prospectus supplement.

EXPERTS

     The consolidated financial statements and management’s assessment of the effectiveness of internal control over financial reporting have been incorporated by reference herein and in the registration statement in reliance upon the reports of Grant Thornton LLP, independent registered public accountants (which reports expressed an unqualified opinion and contain an explanatory paragraph relating to the adoption of Statement of Financial Accounting Standards No. 123(R), Share-Based Payment) upon the authority of said firm as experts in accounting and auditing.

$100,000,000

StemCells, Inc.

Common Stock
Preferred Stock
Warrants
Debt Securities

PROSPECTUS

July 18, 2008

We have not authorized any dealer, salesperson or other person to give any information or represent anything not contained in this prospectus. You must not rely on any unauthorized information. If anyone provides you with different or inconsistent information, you should not rely on it. This prospectus does not offer to sell any shares in any jurisdiction where it is unlawful. Neither the delivery of this prospectus, nor any sale made hereunder, shall create any implication that the information in this prospectus is correct after the date hereof.