Exhibit 32.2


                  CERTIFICATION BY THE CHIEF FINANCIAL OFFICER
                 PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED
            PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002


                                  CERTIFICATION

      Pursuant to 18 U.S.C. Section 1350, the undersigned officer of Merck &
Co., Inc. (the "Company"), hereby certifies that the Company's Quarterly Report
on Form 10-Q for the quarter ended September 30, 2003 (the "Report") fully
complies with the requirements of Section 13(a) or 15(d) of the Securities
Exchange Act of 1934 and that the information contained in the Report fairly
presents, in all material respects, the financial condition and results of
operations of the Company.

Dated:  November 13, 2003            /s/ Judy C. Lewent
                                     --------------------------------
                              Name:  Judy C. Lewent
                              Title: Executive Vice President & Chief
                                     Financial Officer
                                     President, Human Health Asia