8-K

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                      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)          JULY 19, 2001
                                                  ------------------------------

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

                                   NEW JERSEY
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                 (State or Other Jurisdiction of Incorporation)

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

ONE MERCK DRIVE, PO BOX 100, WHITEHOUSE STATION, NJ             08889-0100
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      (Address of Principal Executive Offices)                  (Zip Code)

Registrant's telephone number, including area code              (908) 423-1000
                                                     ---------------------------




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ITEM 5.  OTHER EVENTS

Incorporated by reference is a press release issued by the Registrant on July
19, 2001, attached as Exhibit 99, concerning the Registrant's announcement that
it has completed its acquisition of Rosetta Inpharmatics, Inc.





ITEM 7. FINANCIAL STATEMENTS AND EXHIBITS

     (c)  EXHIBITS

     Exhibit 99       Press release issued              Filed with
                      July 19, 2001                     this document





                                   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:  July 19, 2001                         By: /S/ DEBRA A. BOLLWAGE
                                                 ------------------------------
                                                    DEBRA A. BOLLWAGE
                                                    Assistant Secretary










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                                  EXHIBIT INDEX



Exhibit
Number            Description
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 99               Press release issued July 19, 2001

EX-99

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                                                                      Exhibit 99



Press Contact:    Gwen Fisher                   Investor Contact:  Laura Jordan
                  (908)423-6154                                    (908)423-5185

          MERCK COMPLETES ACQUISITION OF ROSETTA INPHARMATICS, INC.

WHITEHOUSE STATION, N.J., July 19, 2001 - Merck & Co., Inc. (NYSE: MRK)
announced today that it has completed its acquisition of Rosetta Inpharmatics,
Inc. (NASDAQ: RSTA) in a tax-free reorganization.
        Each share of Rosetta stock has been converted into 0.2352 shares of
Merck stock.  The transaction has a net equity value of approximately $540
million.
        To promote the continued success of Rosetta's highly skilled team,
Merck will maintain Rosetta as a wholly owned subsidiary, reporting to Anthony
Ford-Hutchinson, Ph.D., executive vice president, worldwide basic research,
Merck Research Laboratories (MRL).  Stephen Friend, M.D., Ph.D., formerly
Rosetta's chairman and chief executive officer, will be joining Merck as
president of Rosetta, and vice president, basic research, MRL.  Merck will keep
Rosetta's existing facilities in Kirkland and Bothell, Wash. The organization
will continue to operate under the name Rosetta Inpharmatics, Inc.
        "We're extremely pleased to have Rosetta now as part of Merck Research
Laboratories," said Dr. Ford-Hutchinson.  "Rosetta will be a tremendous asset
in helping Merck more efficiently analyze gene data to predict how medical
compounds will interact with different kinds of cells in the body, therefore
potentially allowing Merck scientists to more accurately select drug targets
and speed up the development process."

ABOUT MERCK
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        Merck & Co., Inc. is a leading, research-driven pharmaceutical products
and services company.  Merck discovers, develops, manufactures and markets a
broad range of innovative products to improve human and animal health, directly
and through its joint
                                   - more -

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ventures.  Merck-Medco manages pharmacy benefits for employees, insurers and
other plan sponsors, encouraging the appropriate use of medicines and providing
disease management programs.  Through these complementary capabilities, Merck
works to improve the quality of life and contain overall health care costs.
        This press release contains "forward-looking statements" as that term is
defined in the Private Securities Litigation Reform Act of 1995.  No
forward-looking statement can be guaranteed, and actual results may differ
materially from those projected.  We undertake no obligation to publicly update
any forward-looking statement, whether as a result of new information, future
events, or otherwise.  Forward-looking statements in this document should be
evaluated together with the many uncertainties that affect our businesses,
particularly those mentioned in the cautionary statements in Item 1 of our Form
10-K for the year ended Dec. 31, 2000, and in our periodic reports on Form 10-Q
and Form 8-K (if any) which we incorporate by reference.

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