SecProbe.io

Via Facsimile and U.S. Mail Mail Stop 6010                                                                                                   April 1, 2009   Mr. Simon Bicknell Company Secretary GlaxoSmithKline plc 980 Great West Road Brentford  Middlesex TW8 9GS UNITED KINGDOM
Re: GlaxoSmithKline plc
 Form 20-F for the Year Ended December 31, 2008  Filed March 4, 2009  File No. 001-15170

Dear Mr. Bicknell:

We have reviewed your filing and have the following comment.

Where indicated, we think you should revise your Form 20-F in response to this
comment.  If you disagree, we will consider your explanation as to why our comment is
inapplicable or a revision is unnecessary.  In  our comment, we ask you to provide us with
information so we may better understand your  disclosure.  After reviewing this
information, we may raise additional comments.   Please understand that the purpose of our re view process is to assist you in your
compliance with the applicable disclosure  requirements and to  enhance the overall
disclosure in your filing.  We look forward to  working with you in these respects.  We
welcome any questions you may have about our comment or on any other aspect of our review.  Feel free to call us at the telephone numbers listed at the end of this letter.

Mr. Simon Bicknell
GlaxoSmithKline plc
April 1, 2009 Page 2   Form 20-F filed March 4, 2009

Exhibits, page 212
1. We note that you acquired Reliant Pharmaceuticals, Inc. in December 2007 for
£814 million pounds, but it does not appear that the acquisition agreement has
been filed as an exhibit to your public re ports.  Please file this agreement as an
exhibit to your Form 20-F or provide us with an analysis supporting your
determination that this agreement is not  a material contract.  Please refer to
paragraph 4(a) of the Instructions as to Exhibits on Form 20-F.

*    *    *    *

Please amend your Form 20-F and respond to these comments within 10 business
days or tell us when you will provide us with a response.  Please furnish a cover letter
with your amendment that keys your response to our comment and provide any requested information.  Detailed letters greatly facilitate our review.  Please file your letter on
EDGAR under the form type label CORRESP.   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 all in formation required under
the Securities Exchange Act of 1934 and th at they have provided all information
investors require for an informed invest ment decision.  Since the company and its
management are in possession of all facts re lating to a company’s disclosure, they are
responsible for the accuracy and adequacy of the disclosures they have made.
  In connection with responding to our co mments, please provide, in your letter, a
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 comme nts as a defense in any proceeding
initiated by the Commission or any person under the federal secu rities laws of the
United States.

In addition, please be advise d that the Division of Enfo rcement has access to all
information you provide to the staff of the Divi sion of Corporation Fi nance in our review
of your filing or in response to our comment on your filing.

Mr. Simon Bicknell
GlaxoSmithKline plc April 1, 2009 Page 3
 Please contact Nandini Acharya, Sta ff Attorney at (202) 551-3495, Daniel
Greenspan, Special Counsel at (202) 551-3623 or me at (202) 551-3715 with any
questions.

 Sincerely,

Jeffrey P. Riedler Assistant Director