Ownership Submission
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
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(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)
02/25/2005
(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               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  

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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 2005/02/25 (right to buy) $ 31.84 02/25/2005   A   250,000   02/25/2006(5) 02/24/2015 Common Stock 250,000 $ 0 250,000 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   03/01/2005
**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.
(5) The option vests in three equal annual installments beginning February 25, 2006.

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