Merck & Co., Inc

One Merck Drive

P.O. Box 100, WS 3B-35

Whitehouse Station, NJ 08889-0100

Tel 908-423-3853

Fax 908-423-3352

August 25, 2006

Mr. Jim B. Rosenberg
Senior Assistant Chief Accountant
United States Securities and Exchange Commission
100 First Street, N.E.
Washington, DC 20549

Re:  Merck & Co., Inc.
       Form 10-K for the Year
       Ended December 31, 2005

Dear Mr. Rosenberg:

The Company has received your August 21, 2006 comment letter. This is to confirm that the Company intends to respond to your letter by September 15, 2006.

Very truly yours,

/s/  Jon Filderman

Jon Filderman
Counsel, Corporate Legal Group