SecProbe.io

July 8, 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 Form 10-Q for the Quarterly Period Ended March 31, 2011 Filed May 9, 2011 File No. 001-06571

Dear Mr. Kellogg:
 We have limited our review of your filings to  those issues we have addressed in our
comments.  In our comments, we ask you to pr ovide us with information so we may better
understand your disclosure.
 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.

Form 10-K for the Fiscal Year Ended December 31, 2010

 Business

 Research and Development, 15

 1. Regarding the chart of your current research  pipeline at page 21, for each late stage
research and development drug listed please provide us proposed disclosure to be
included in future periodic re ports showing  the following:

 The month and year the drug candidate ente red phase III clinical development; and
 Any significant patents associated with th e drug candidates and the related expiration
dates.

Mr. Peter N. Kellogg
Merck & Co., Inc. July 8, 2011 Page 2
 Management’s Discussion and Analysis of Fi nancial Condition and Results of Operations

 Research and Development, page 61

 2. In order to help us evaluate your disclosu re about the resources that you expend in your
research and development activities, please provide us the composition of research and
development expenses incurred during 2010 and 2009 other than those that you
separately explain (i.e. IPR&D impairment , restructuring activities and the ARIAD
agreement).  In this regard, please provide us  a break-out, if practicable, by development
phase (i.e. preclinical versus clinical),  by therapeutic class or by some other
function/nature for which you report these costs internally.
Analysis of Liquidity and Capital Resources, page 75

 3. You state on page 151 “at December 31, 2010, foreign earnings of $40.4 billion have
been retained indefinitely by subsidiary comp anies for reinvestment.”  You further state
that “a large portion of the cash and investments are held in foreign ju risdictions.”  Please
provide proposed disclosure to  be included in future peri odic reports of the amount of
cash and investments that are currently held  by your foreign subs idiaries that are
considered reinvested indefinitely and its expected effect on your liquidity and capital
resources.

Notes to the Consolidated Financial Statements

 Note 12. Contingencies and Environmental Liabilities, page 124

 4. Throughout your footnote you disclose for vari ous litigation that unfavorable outcomes
“could have a material adverse effect” on th e Company’s financial position, liquidity and
results of operations.  For lo ss contingencies where you have made this assertion, please
address the following:
 Please provide us with proposed disclosure  to be included in future periodic
reports of the amount or range of reasonabl y possible loss, as that term is defined
by ASC 450-20.
 For those matters that you conclude that  you cannot estimate an amount or range
of reasonably possible loss, please provide us proposed disclosure to be included
in future periodic reports in accord ance with ASC 450-20 that makes this
assertion.  For those matters, also provide us an explanation of the procedures you
undertake on a quarterly basi s to attempt to develop an amount or range of
reasonably possible loss.

5. You disclose in your first quarter 2011 Form 10-Q that you paid Johnson & Johnson a
one-time payment of $500 million in relation to your Centocor Distribution Agreement
arbitration.  You disclose in your Decem ber 31, 2010 Form 10-K that an unfavorable
outcome would have a material adverse eff ect, which would infer that you had data in
order to base this assertion.  Tell us why you did not disclose an estimate of the amount
of loss or range of loss at December 31, 2010. In  addition, tell us why you did not accrue

Mr. Peter N. Kellogg
Merck & Co., Inc. July 8, 2011 Page 3
 an amount at December 31, 2010.  Include, in yo ur response, a chronology of the facts
and circumstances leading from the time you filed your Form 10-K for the year ended
December 31, 2010 to the payment of the settlement.

6. Please refer to your disclosure under the capti on “other litigation” on page 135 that “all
such proceedings are either adequately covere d by insurance or, if not so covered, should
not ultimately result in any liability that would have a material adverse effect on the
financial position, liquidity or  results of operations of the Company” and tell us:

 Whether this disclosure means that th e amount or range of reasonably possible
loss, as these terms are used in ASC 450-20, is not material to your financial
statements and if so, provide us proposed  disclosure to be included in future
periodic reports to clarify. If not, provide us  proposed disclosure that satisfies the
disclosure requirements of ASC 450-20; and
 Whether your assessment of materiality is based on the amount or range of
reasonably possible loss without  giving effect to anticipat ed insurance recoveries,
and if so, provide us proposed disclosure to be included in future periodic reports
to clarify. If not, provide us proposed disclosure that  satisfies the disclosure
requirements of ASC 450.

Note 17. Taxes on Income, page 148
 7. Refer to your $40.4 billion of retained indefi nitely foreign earnings. Provide us proposed
disclosure to be included  in future period reports as required by ASC 740-30-50-2.
 Form 10-Q for the Quarter Ended March 31, 2011

 Notes to the Consolidated Financial Statements

Note 5. Financial Instruments
Concentration of Credit Risk, page 13

8. Refer to your disclosure regard ing the concentration of cred it risk related to outstanding
receivables at March 31, 2011 from certain EU countries  totaling approximately $1.5
billion or approximately 19% of your acc ounts receivables balance, of which $285
million have been outstanding for more than a y ear.  Tell us how much you have reserved
in your allowance for doubtful accounts at March 31, 2011, which we note is $111 million, related to these r eceivables and why you believe the amount reserved is
appropriate.  Further, describe  for us management’s plans a nd options available to collect
these past due receivables and the expected  effects of these customers on your future
financial position and results of opera tions including reduction in sales.

We urge all persons who are responsible for the accuracy and adequacy of the
disclosure in the filing to be certain that the filing includes the information the Securities
Exchange Act of 1934 and all applicable Exchan ge Act rules require.  Since the company and
its management are in possession of all facts relating to a co mpany’s disclosure, they are
responsible for the accuracy and adequacy of the disclosures they have made.

Mr. Peter N. Kellogg
Merck & Co., Inc. July 8, 2011 Page 4
  In responding to our comments, please provi de a written statement from the company
acknowledging that:
 the company is responsible for the adequacy  and accuracy of the disclosure in the
filing;
 staff comments or changes to disclosure  in response to staff comments do not
foreclose the Commission from taking any action with respect to the filing; and
 the company may not assert staff comments as a defense in any proceeding initiated
by the Commission or any person under the federal securities laws of the United States.

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