SecProbe.io

April 2, 2015

Via E -mail
Mr. Simon Dingemans
Chief Financial  Officer
GlaxoSmithKline plc
980 Great West Road
Brentford
Middlesex
TW8 9GS
United Kingdom

Re: GlaxoSmithKline plc
 Form 20-F for the Fiscal Year Ended December 31 , 2014
Filed February 27, 2015
 File No. 1-15170

Dear Mr. Dingemans :

We have limited our review to only your financial statements and related disclosures and
have the following comments .  In our comment s, we ask you to provide us with information so
we may better understand your disclosure.

Please respond to this letter within 10 business days by providing the requested
information or by advising us when you will provide the requested resp onse.  If you do not
believe a  comment applies to your facts and circumstances, please tell us why in your response.
Please furnish us a letter on EDGAR under the form type label CORRESP that keys your
response s to our comment s.

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

Exhibit 15.2:  GSK Annual Report 2014
Notes to financial statements

Note 14: Taxation, page 156

1. Please tell us why the reconciling items for differences in overseas taxation rates and the
benefit of intellec tual property incentives changed  so significantly as a percentage of
profit before tax from 2013 to 2014.  In your response, please:
 identify the significant jurisdictions contributing to the increase in the tax rate
associated with overseas taxes;  and

Mr. Simon Dingemans
GlaxoSmithKline plc
April 2, 2015
 Page 2

  describe patent box regimes , explain why they impact your effective tax rate so
significantly in 2014, and quantify  their impact on you r effective tax rate by
significant regime .

Note 18: Goodwill, page 160

2. In the first paragraph on page 161 you disclose that you use post -tax cash flows and post -
tax discount rates when you utilize value in use in your goodwill impairment testing.
Pleas e explain to us how your use of post -tax inputs in your determination of value in use
complies with paragraphs 50 and 55 of IAS 36 which requires e stimates of future cash
flows and the discount rate to be determined on a pre -tax basis.  Please provide us
proposed disclosure to be included in future periodic reports that asserts in your
accounting policy note that the use of post -tax assumptions does not result in a value in
use that is materially different had pre -tax assumptions been used.  Also disclose t he
post-tax and pre -tax discount rates used.

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

 In responding t o our comment s, please provide  a written statement from the company
acknowledging that:

 the company is responsible for the adequacy and accuracy of the disclosure in the filing;
 staff comment s or changes to disclosu re in response to staff comment s do not foreclose
the Commission from taking any action with respect to the filing; and
 the compa ny may not assert the staff comment s as a defense in any proceeding initiated
by the Commission or any person under the federal securities laws of the United S tates.

You may contact Mark Brunhofer, Senior Staff Accountant , at (202) 551 -3638  or Lisa
Vanjoske , Assistant Chief Account ant, at (202) 551 -3614 if you have questions regarding the
comment s.  In this regard, do not hesitate to contact me at (202) 551 -3679.

Sincerely,

        /s/ Jim B. Rosenberg

Jim B. Rosenberg
Senior Assistant Chief Accountant