Transaction in Own Shares

GlaxoSmithKline PLC
21 March 2006



GlaxoSmithKline plc (the "Company") announces that in accordance with the
authority granted by shareholders at the Company's Annual General Meeting on
25th May 2005 it purchased 1,000,000 of its Ordinary shares of 25 pence each
("shares") on 21 March 2006 at a price of 1533.00 pence per share.

The Company intends to hold these shares in Treasury.

Following the purchase of these shares, the Company holds 153,464,678 of its
shares in Treasury and has 5,820,060,398 shares in issue (excluding Treasury
shares).

This announcement does not constitute, or form part of, an offer or any
solicitation of an offer to purchase or subscribe for securities in any
jurisdiction.



                      This information is provided by RNS
            The company news service from the London Stock Exchange