Director/PDMR Shareholding

Notification of Transactions of Directors, Persons Discharging Managerial Responsibility or Connected Persons

I give below details of the change in interests in the Ordinary shares of GlaxoSmithKline plc in respect of the under-mentioned person:

Mr M Dunoyer sold 18,889 Ordinary shares on 25 August 2010 at a price of £12.00 per share.

The Company and the above named individual were advised of this transaction on 25 August 2010.

This notification relates to a transaction notified in accordance with Disclosure and Transparency Rule 3.1.4R(1)(a).

S M Bicknell

Company Secretary

25 August 2010