SecProbe.io

May 15, 201 4

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

Re: GlaxoSmithKline plc
  Form 2 0-F for Fis cal Year Ended December 31, 2013
Filed February 28, 2014
  File No. 001 -15170

Dear  Mr. Dingemans :

We have reviewed  your filing 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 response.   If you do not
believe  a comment applies to your facts and circumstances, please tell us why in you r 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 provided, we may raise additional comments and/or
request that you amend your filing.

Exhibit 15,1
Financial Review 2013
Total results
Costs of Sales, page 66

1. Your gross profit as a percentage of turnover decreased from 72% in 2011 to 70% in
2012 and 67.6% in 2013.  Please  point us to disclosure in your filing that discusses
whether or no t this trend is reasonably likely to continue in the future and why  or why
not, or tell us why disclosure is not necessary.

Mr. Simon Dingemans
GlaxoSmithKline plc
May 15, 201 4
Page 2

 Taxation, page 67

2. Please refer to the decrease in  your effective tax rate from 29.1% for 201 2 to 15.3% for
2013 .  Tell us whethe r the non-cash deferred tax charges of £422  million  in 2012 and
deferred tax credits of £393  million  in 2013  account for the 6.3% increase and 5.6%
decrease in the rate reconciliation in Note 14 , Taxation , to your consolidated financial
statements on page 152 in 2012 and 2013 , respectively .  Also, please  provide us an
analysis , for each year,  that more precisely  explains  the nature  of these items , the reason
that they impact the effective tax rate  and the e xtent to which future periods  could be
impacted .

Item 8. Financial Information
Notes to Consolidated Financial Statements
40 Commitments
Contractual Obligations and Commitments, page 187

3. Please refer to your commitments related to intangible assets totaling £7.1 billion as of
December 31, 2013 , which are “dependent upon successful clinical development or on
meeting specified sales targets”  and p rovide us the following information:
 Separately quantify for us the portion of the £7.1 billion  that represents clinical
development versus specified sales targets.
 Summarize for us your accounting policies for recognizing these commitments, the
amount of commitments  recognized during 2011,  2012 and 2013 and where in your
financial statements  these amounts are classified.
 Summarize for us  other amounts and their nature  and financial statement
classification recognized in 2011, 2012 and 2013 underlying the arrangements for
these commitments.
Where appropriate reference for us the authoritative literature you relied upon to support
your accounting and classification.

We urge all persons who are responsible for the accuracy and adequacy of the disclosure
in the filing to be certain that t he filing  include s the information the Securities Exchange Act of
1934 and all applicable 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 accu racy
and adequacy of the disclosures they have made.

  In responding to our comments, 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 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

Mr. Simon Dingemans
GlaxoSmithKline plc
May 15, 201 4
Page 3

  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.

Please contact Frank Wyman, Staff Accountant, at (202) 551 -3660  or Mark Brunhofer,
Senior Staff Accountant, at (202) 551 -3638 , if you have any questions regarding the comments .
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