Director/PDMR Shareholding

GlaxoSmithKline PLC
21 February 2008









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





I give below details of changes in the interests of Dr M Slaoui, a Person
Discharging Managerial Responsibility, in the Ordinary shares of GlaxoSmithKline
plc arising from transactions which took place on 20 February 2008:-



Dr Slaoui's connected person sold 280 shares at a price of £11.40 per share to
meet her tax liabilities following the vesting of a Performance Share Plan
award.



The Company and Dr Slaoui's connected person were advised of these transactions
on 21 February 2008.



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





S M Bicknell

Company Secretary



21 February 2008


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