SecProbe.io

September 9, 2011
 Via E-mail

Mr. Peter N. Kellogg Executive Vice President and  Chief Financial Officer Merck & Co., Inc. One Merck Drive Whitehouse Station, NJ  08889-0100
Re: Merck & Co., Inc.
Form 10-K for the Fiscal Year Ended December 31, 2010 Filed February 28, 2011 File No. 1-06571

Dear Mr. Kellogg:
 We have reviewed your August 5, 2011 res ponse to our July 8, 2011 letter and have
the following comments.
 Please respond to this letter within te n business days by providing the requested
information or by advising us when you will provide the requested response.  If you do not believe a comment applies to your facts a nd circumstances, please tell us why in your
response.  Please furnish us a letter on EDGA R under the form type label CORRESP that
keys your responses to our comments.

After reviewing the information you provide in response to these comments, we may
have additional comments and/or request that you amend your filing.

Research and Development, 15

 1. We acknowledge your response to our prior co mment 2.  Please confirm to us that you
will revise your disclosure in future filings to disclose the information provided in your response.
 Note 12. Contingencies and Environmental Liabilities, page 124

 2. Refer to your response to prior comment 5, your  disclosure, in your Form 10-K for the
year ended December 31, 2010, of the Centoc or Distribution Agreement contingency
which you ultimately settled on April 15, 2011 did not appear to comply with ASC 450-20-50-4 as you did not disclose an estimate of the possible loss or  range of loss or a
statement that such an estimate cannot be ma de. We believe your disclosures about other
matters unresolved can be improved. We have  read your response to comment 4 that
discusses your inability to estimate the possi ble loss or range of loss with respect to
Vioxx related matters and Vytorin/Zetia (Enhanc e) litigation.  Your response does not

Mr. Peter N. Kellogg
Merck & Co., Inc. September 9, 2011 Page 2
 address disclosure as required by ASC 450-20-50- 4 with respect to all other litigation.
Please provide us proposed disclosure to be in cluded in future periodic reports of the
amount or range of reasonably possible loss for all unresolved matters including Fosamax
and NuvaRing, either individually or in the a ggregate, or state that such an estimate
cannot be made.  For those matters includi ng Vioxx related matters and Vytorin/Zetia
(Enhance) litigation that you conclude that you cannot estimate the amount or range of
reasonably possible loss, pl ease address the following:
 Whether or not there are any matters for whic h the additional loss is  either remote or
immaterial;
 For those matters for which additiona l loss is not remote or immaterial:
o what specific factors are preventing you from estimating a range and when you
expect the factors preventing you from es timating any range to be alleviated;
o The status of any negotia tions and whether or not loss amounts have been
exchanged;
o The nature of any internal discussions on these matters and whether or not they
include loss estimates; and
o Whether or not you have obtained studi es to estimate the amount of losses
associated with any matters that involve a large number of claimants and what these studies suggest.

You may contact Christine Allen, Staff A ccountant, at (202) 551-3652 or Melissa N.
Rocha, Accounting Branch Chief, at (202) 551-3854 if you have quest ions regarding the
comments.   In this regard, do not he sitate to contact me at (202) 551-3679.

Sincerely,
   /s/ Jim B. Rosenberg
 Jim B. Rosenberg Senior Assistant Chief Accountant