FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: January 31, 2005 Estimated average burden hours per response... 0.5

(Print or Type Responses)

1. Name and Address of Reporting Person * GILMARTIN RAYMOND V   2. Issuer Name and Ticker or Trading Symbol MERCK & CO INC [(MRK)] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) COB, President, CEO (Last) (First) (Middle) ONE MERCK DRIVE, P.O. BOX 100 3. Date of Earliest Transaction (Month/Day/Year) 02/01/2005 (Street) WHITEHOUSE STATION, NJ 08889-0100 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 02/01/2005   M   379,796 A $ 20.0831 829,891 D   Common Stock               155,570 (1) I By FLP Common Stock               23,200 (2) I By Spouse Common Stock - 401(k) Plan               7,590.4403 (3) I By 401(k) Common Stock - Dividend Reinvestment               11,799.393 (4) D

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
	Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.		SEC 1474 (9-02)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Employee Stock Option 1995/02/28 (right to buy)

$ 20.0831

02/01/2005

M

379,796

02/28/2000

02/27/2005

Common Stock

379,796

$ 0

0

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
GILMARTIN RAYMOND V ONE MERCK DRIVE P.O. BOX 100 WHITEHOUSE STATION, NJ 08889-0100	X		COB, President, CEO

Signatures

Debra A. Bollwage as Attorney-in-Fact for Raymond V. Gilmartin		02/02/2005
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Gilmartin Family Partnership, L.P. (FLP), a limited partnership of which the reporting person and his wife are the sole partners and sole limited partners. Limited partnership interests representing a 15% interest in FLP is held in a trust of which the reporting person's wife is the sole trustee for the benefit of the reporting person's children and grandchildren. Reporting person disclaims beneficial ownership of shares held by FLP to the extent of the trust's interest in FLP.
(2)	Beneficial ownership as to these shares is disclaimed.
(3)	Includes shares acquired and dividends earned through January 3, 2005 in the Merck & Co., Inc. Employee Savings and Security Plan, a 401(k) plan.
(4)	Includes shares held and dividends earned through January 3, 2005 in the Merck Stock Investment Plan.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.