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

                                    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 27, 2004

                                MERCK & CO., Inc.
             (Exact Name of Registrant as Specified in Its Charter)

                                   New Jersey
                 (State or Other Jurisdiction of Incorporation)

                    1-3305                              22-1109110
           (Commission File Number)         (I.R.S. Employer Identification No.)

One Merck Drive, PO Box 100, Whitehouse Station, NJ     08889-0100
     (Address of Principal Executive Offices)           (Zip Code)

        Registrant's Telephone Number, Including Area Code (908) 423-1000

Item 7. Financial Statements and Exhibits.

      (c) Exhibits

      Exhibit 99.1      Press release issued January 27, 2004 regarding earnings
                        for fourth quarter 2003

      Exhibit 99.2      Certain supplemental information not included in the
                        press release

Item 9. Regulation FD Disclosure; and

Item 12. Results of Operations and Financial Condition.

The following information is being furnished pursuant to both Item 9 and Item
12.

Incorporated by reference is a press release issued by the Registrant on
January 27, 2004, regarding earnings for the fourth quarter 2003, attached as
Exhibit 99.1. Also incorporated by reference is certain supplemental information
not included in the press release, attached as Exhibit 99.2.

This information shall not be deemed to be "filed" for purposes of Section 18 of
the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or
otherwise subject to the liabilities of that Section, and is not incorporated by
reference in any filing under the Securities Act of 1933, as amended, or the
Exchange Act, except as expressly set forth by specific reference in such
filing.

                                   SIGNATURES

      Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                         MERCK & CO., Inc.




Date: January 27, 2004                   By: /s/ Debra A. Bollwage
                                            ------------------------------------
                                             DEBRA A. BOLLWAGE
                                             Assistant Secretary

                                  EXHIBIT INDEX



Exhibit
Number      Description
------      -----------
         
99.1        Press release issued January 27, 2004 regarding earnings for fourth
            quarter 2003

99.2        Certain supplemental information not included in the press release