Buy-Back Programme

GlaxoSmithKline PLC
31 March 2008

GlaxoSmithKline plc - Share Buy-Back Programme



GlaxoSmithKline plc (the "Company") announces that it has today put in place an
irrevocable, non-discretionary programme for the purchase of its Ordinary shares
during the close period which precedes the 2008 first quarter results
announcement, expected to be made on 23 April 2008.  The shares purchased on
behalf of the Company are for cancellation.



The aim of the programme is to reduce the issued share capital of the Company to
help enhance returns for shareholders.



The share buy-back programme will be managed by an independent third party which
makes its trading decisions in relation to the Company's securities
independently of, and uninfluenced by, the Company.



Any purchases pursuant to these arrangements will be effected during the period
between 1 April 2008 and 23 April 2008 within certain pre-set parameters and in
accordance with both the Listing Rules and the limitations of the repurchase
authority granted to the Directors at the last Annual General Meeting of
shareholders.  The Company confirms that it currently has no inside information.



SM Bicknell

Company Secretary



31 March 2008


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