Director/PDMR Shareholding

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

I give below details of a change in the interests of a Person Discharging Managerial Responsibility in American Depositary Shares (ADSs) of GlaxoSmithKline plc on 22 March 2013:

Mr W C Louv The sale of 16,000 ADSs in GlaxoSmithKline plc at a price of $46.44 per ADS.

The Company and the above mentioned individual were advised of this transaction on 22 March 2013.

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

V A Whyte

Company Secretary

25 March 2013