UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

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                                    FORM 8-K

                                 CURRENT REPORT
                       Pursuant to Section 13 or 15(d) of
                       the Securities Exchange Act of 1934

       Date of Report (Date of earliest event reported): January 25, 2009
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                                   PFIZER INC.
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             (Exact name of registrant as specified in its charter)



    Delaware                         1-3619                    13-5315170
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(State or other             (Commission File Number)          (IRS Employer
jurisdiction of                                           Identification Number)
 incorporation)


              235 East 42nd Street, New York, New York       10017
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              (Address of  principal executive offices)   (zip code)


       Registrant's telephone number, including area code:    (212) 573-2323
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                                 Not Applicable
          -------------------------------------------------------------
          (Former name or former address, if changed since last report)


        Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions:

|X| Written communications pursuant to Rule 425 under the Securities Act (17 CFR
230.425)

|_| Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR
240.14a-12)

|_| Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange
Act (17 CFR 240.14d-2(b))

|_| Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange
Act (17 CFR 240.13e-4(c))



Item 1.01 Entry into a Material Definitive Agreement.

        Pfizer Inc., a Delaware corporation (the "Company"), Wagner Acquisition
Corp., a Delaware corporation and direct wholly-owned subsidiary of the Company
("Merger Sub"), and Wyeth, a Delaware corporation ("Wyeth"), have entered into a
definitive Agreement and Plan of Merger (the "Merger Agreement") dated as of
January 25, 2009. Pursuant to the Merger Agreement and subject to the conditions
set forth therein, Merger Sub will merge with and into Wyeth (the "Merger"),
with Wyeth surviving as a wholly-owned subsidiary of the Company.

        As a result of the Merger, each outstanding share of Wyeth's common
stock, other than shares of restricted stock (which will be entitled to receive
cash consideration pursuant to separate terms of the Merger Agreement), and
shares of common stock held directly or indirectly by the Company or Wyeth
(which will be cancelled as a result of the Merger), and other than those shares
with respect to which appraisal rights are properly exercised and not withdrawn,
will be converted into the right to receive $33.00 in cash (the "Cash
Consideration"), without interest, and 0.985 validly issued, fully paid and
non-assessable shares of common stock of the Company (the "Stock
Consideration"). Under the terms of the Merger Agreement, in the event that the
number of shares of common stock of the Company issuable as a result of the
Merger would exceed 19.9% of the outstanding shares of common stock of the
Company immediately prior to the closing of the Merger, the Stock Consideration
will be reduced so that no more than 19.9% of the outstanding shares of common
stock of the Company become issuable in the Merger and the Cash Consideration
will be increased by a corresponding amount.

        The completion of the Merger is subject to certain conditions,
including, among others, (i) adoption of the Merger Agreement by Wyeth's
stockholders, (ii) the absence of certain legal impediments to the consummation
of the Merger, (iii) the expiration or termination of the applicable waiting
period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as
amended, and obtaining antitrust approvals in certain other jurisdictions, (iv)
subject to certain materiality exceptions, the accuracy of the representations
and warranties made by the Company and Wyeth, respectively, and compliance by
the Company and Wyeth with their respective obligations under the Merger
Agreement, (v) declaration of the effectiveness by the Securities and Exchange
Commission of the Registration Statement on Form S-4 to be filed by the Company;
and (vi) the lenders providing the Company with debt financing in connection
with the Merger shall not have declined to provide such financing at closing due
to the occurrence of a Parent Material Adverse Effect (as defined in the Merger
Agreement) or due to the Company's failing to obtain (A) an unsecured long-term
obligations rating of at least "A2" (with stable (or better) outlook) and a
commercial paper credit rating of at least "P-1" (which rating shall be
affirmed) from Moody's Investors Services, Inc. and (B) a long-term issuer
credit rating of at least "A" (with stable (or better) outlook) and a short-term
issuer credit rating of at least "A-1" (which rating shall be affirmed) from
Standard & Poor's Ratings Group (it being understood that an unsecured long
-term obligations rating of higher than "A2" and a long-term issuer credit
rating of higher than "A" shall satisfy the foregoing condition, as applicable,
irrespective of whether or not such rating(s) are subject to "negative watch" or
"negative outlook") (the "Specified Financing Condition").

        Each of the Company and Wyeth has made representations and warranties in
the Merger Agreement. Wyeth has agreed to various covenants and agreements,
including, among other things (i) to conduct its business in the ordinary course
of business during the period between the execution of the Merger Agreement and
the closing of the Merger and (ii) not to solicit alternate transactions. The
Company has also agreed to various covenants and agreements, including, among
other things (i) to conduct its business in the ordinary course of business
during the period between the execution of the Merger Agreement and the closing
of the Merger and (ii) not to engage in acquisitions or share repurchases above
certain agreed thresholds. Additionally, the Company is required to reduce its
quarterly dividend to no more than $0.16 per share.

        The Merger Agreement contains specified termination rights for the
parties. If the Merger Agreement is terminated in certain circumstances where
Wyeth receives an acquisition proposal that the board of directors of Wyeth
determines is, or is reasonably likely to lead to, a Superior Proposal (as
defined in the Merger Agreement), then Wyeth would be required to pay the
Company a termination fee of (i) $1.5 billion if such proposal is received
during the first 30 days following execution of the Merger Agreement or (ii) $2
billion if such proposal is received after the first 30 days following execution
of the Merger Agreement. Wyeth would also be required to pay the Company a
termination fee of $2 billion if (1) the Merger Agreement is terminated due to
either the failure of Wyeth's shareholders to approve the Merger or Wyeth's
breach of the Merger Agreement, and in each case, certain additional
circumstances occur, and (2) within twelve months following such termination,
Wyeth enters into a definitive agreement with a third party with respect to
certain extraordinary transactions or certain extraordinary transactions are
consummated. In addition, if as a result of an Intervening Event (as defined in
the Merger Agreement) Wyeth's board of directors changes its recommendation that
its shareholders approve the Merger, then the Company may terminate the Merger
Agreement, in which case Wyeth would be required to pay the Company a $2 billion
termination fee and reimburse the Company for up to $700 million of expenses
incurred by the Company in connection with the Merger.

        If all conditions to the Merger Agreement are satisfied other than the
Specified Financing Condition and the Company does not consummate the Merger
within the period specified in the Merger Agreement, then the Merger Agreement
may be terminated by Wyeth, in which case the Company would be required to pay
Wyeth a termination fee of $4.5 billion.

        Additionally, the Company has agreed that it will cause two current
directors of Wyeth to be appointed to the board of directors of the Company at
the closing of the Merger.

        The foregoing description of the Merger Agreement and the transactions
contemplated thereby is not complete and is subject to and qualified in its
entirety by reference to the Merger Agreement, a copy of which is attached
hereto as Exhibit 2.1 and the terms of which are incorporated herein by
reference.

        The Merger Agreement has been included to provide investors and security
holders with information regarding its terms. It is not intended to provide any
other financial information about the Company, Wyeth, or their respective
subsidiaries and affiliates. The representations, warranties and covenants
contained in the Merger Agreement were made only for purposes of that agreement
and as of specific dates; were solely for the benefit of the parties to the
Merger Agreement; may be subject to limitations agreed upon by the parties,
including being qualified by confidential disclosures made for the purposes of
allocating contractual risk between the parties to the Merger Agreement instead
of establishing these matters as facts; and may be subject to standards of
materiality applicable to the contracting parties that differ from those
applicable to investors. Investors should not rely on the representations,
warranties and covenants or any description thereof as characterizations of the
actual state of facts or condition of the Company, Merger Sub or Wyeth or any of
their respective subsidiaries or affiliates. Moreover, information concerning
the subject matter of the representations, warranties and covenants may change
after the date of the Merger Agreement, which subsequent information may or may
not be fully reflected in public disclosures by the Company and Wyeth.


Item 8.01. Other Events.

Financing Commitments

        On January 25, 2009, the Company entered into a bridge term facility
commitment letter (the "Bridge Term Facility Commitment Letter") pursuant to
which a syndicate of banks comprised of J.P. Morgan Securities Inc., JPMorgan
Chase Bank, N.A., Banc of America Securities LLC, Bank of America, N.A.,
Barclays Bank PLC, Citigroup Global Markets Inc. and Goldman Sachs Credit
Partners L.P. (together, the "Initial Bridge Lenders") have committed to provide
a portion of the financing for the transactions contemplated by the Merger
Agreement. The Bridge Term Facility Commitment Letter provides that the Initial
Bridge Lenders will commit to provide $22.5 billion under an unsecured bridge
term facility (the "Bridge Term Facility"). The commitment is subject to various
conditions, including no Company Material Adverse Effect (as defined in the
Merger Agreement) or Parent Material Adverse Effect (as defined in the Merger
Agreement) having occurred, the maintenance by the Company of the credit ratings
set forth in the Specified Financing Condition and other closing conditions.

        In addition, on January 25, 2009, the Company entered into a revolving
credit facility commitment letter (the "Revolving Credit Facility Commitment
Letter") pursuant to which a syndicate of banks comprised of J.P. Morgan
Securities Inc., JPMorgan Chase Bank, N.A., Banc of America Securities LLC, Bank
of America, N.A., Barclays Bank PLC, Citigroup Global Markets Inc. and Goldman
Sachs Credit Partners L.P. (together, the "Initial Revolving Lenders") have
committed to provide a portion of the financing for an unsecured revolving
credit facility (the "Revolving Credit Facility") that is intended to refinance
and replace an existing credit facility. The Revolving Credit Facility
Commitment Letter provides that the Initial Revolving Lenders will commit to
provide a portion of the up to $4.0 billion total commitments under the
Revolving Credit Facility and use their commercially reasonable efforts to
arrange a syndicate of lenders to underwrite the balance of the commitments
under the Revolving Credit Facility. The commitment is subject to various
conditions, including obtaining commitments for the uncommitted portion of the
Revolving Credit Facility, the Specified Financing Condition and other closing
conditions.

        In connection with the syndication of the Bridge Term Facility and the
Revolving Credit Facility, the Company will provide potential lenders with the
summary descriptions for each facility, attached hereto as Exhibits 99.1 and
99.2. The summary term sheets for the Bridge Term Facility and the Revolving
Credit Facility summarize certain basic proposed terms of the facilities and are
not intended to be a definitive list of all of the terms of and conditions to
the proposed facilities. Moreover, the proposed terms and conditions set forth
in the term sheets are subject to change.



Forward Looking Statements

This document includes "forward-looking statements" within the meaning of the
safe harbor provisions of the United States Private Securities Litigation Reform
Act of 1995. Such statements may include, but are not limited to, statements
about the benefits of the proposed Merger between the Company and Wyeth,
including future financial and operating results, the combined company's plans,
objectives, expectations and intentions and other statements that are not
historical facts. Such statements are based upon the current beliefs and
expectations of the Company's and Wyeth's managements and are subject to
significant risks and uncertainties. Actual results may differ from those set
forth in the forward-looking statements.

The following factors, among others, could cause actual results to differ from
those set forth in the forward-looking statements: the possibility that the
expected synergies from the proposed Merger of the Company and Wyeth will not be
realized, or will not be realized within the expected time period, due to, among
other things, the impact of pharmaceutical industry regulation and pending
legislation that could affect the pharmaceutical industry; the ability to obtain
governmental and self-regulatory organization approvals of the Merger on the
proposed terms and schedule; the failure of Wyeth stockholders to approve the
Merger; the risk that the businesses will not be integrated successfully;
disruption from the Merger making it more difficult to maintain business and
operational relationships; the possibility that the Merger does not close,
including, but not limited to, due to the failure to satisfy the closing
conditions; the Company's and Wyeth's ability to accurately predict future
market conditions; dependence on the effectiveness of the Company's and Wyeth's
patents and other protections for innovative products; the risk of new and
changing regulation and health policies in the U.S. and internationally and the
exposure to litigation and/or regulatory actions. Additional factors that could
cause results to differ materially from those described in the forward-looking
statements can be found in the Company's 2007 Annual Report on Form 10-K,
Wyeth's 2007 Annual Report on Form 10-K and each company's other filings with
the Securities and Exchange Commission (the "SEC") available at the SEC's
Internet site (http://www.sec.gov).


Additional Information

In connection with the proposed Merger, the Company will file with the SEC a
Registration Statement on Form S-4 that will include a proxy statement of Wyeth
that also constitutes a prospectus of the Company. Wyeth will mail the proxy
statement/prospectus to its stockholders. The Company and Wyeth urge investors
and security holders to read the proxy statement/prospectus regarding the
proposed Merger when it becomes available because it will contain important
information. You may obtain copies of all documents filed with the SEC regarding
this transaction, free of charge, at the SEC's website (www.sec.gov). You may
also obtain these documents, free of charge, from the Company's website,
www.pfizer.com, under the tab "Investors" and then under the tab "SEC Filings".
You may also obtain these documents, free of charge, from Wyeth's website,
www.wyeth.com, under the heading "Investor Relations" and then under the tab
"Financial Reports/SEC Filings".

The Company, Wyeth and their respective directors, executive officers and
certain other members of management and employees may be soliciting proxies from
Wyeth stockholders in favor of the Merger. Information regarding the persons who
may, under the rules of the SEC, be deemed participants in the solicitation of
the Wyeth stockholders in connection with the proposed Merger will be set forth
in the proxy statement/prospectus when it is filed with the SEC. You can find
information about the Company's executive officers and directors in its
definitive proxy statement filed with the SEC on March 14, 2008. You can find
information about Wyeth's executive officers and directors in its definitive
proxy statement filed with the SEC on March 14, 2008. You can obtain free copies
of these documents from the Company and Wyeth using the contact information
above.


Item 9.01. Financial Statements and Exhibits.

(d)     Exhibits

Exhibit No.           Description
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    2.1               Agreement and Plan of Merger among Pfizer Inc., Wagner
                      Acquisition Corp. and Wyeth, dated January 25, 2009.

    99.1              Summary of the Bridge Term Facility.

    99.2              Summary of the Revolving Credit Facility.


                                   SIGNATURES


Under the requirements of the Securities Exchange Act of 1934, the registrant
has caused this report to be signed on its behalf by the authorized undersigned.


                            PFIZER INC.



                            By: /s/ Matthew Lepore
                                ------------------------------------------------
                                Name: Matthew Lepore
                                Title: Vice President, Chief Counsel-Corporate
                                       Governance, and Assistant General Counsel

Dated: January 29, 2009



                                   PFIZER INC.

                                    FORM 8-K


                                 CURRENT REPORT


                                  EXHIBIT INDEX


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Exhibit No.           Description
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    2.1               Agreement and Plan of Merger among Pfizer Inc., Wagner
                      Acquisition Corp. and Wyeth, dated January 25, 2009.

    99.1              Summary of the Bridge Term Facility.

    99.2              Summary of the Revolving Credit Facility.