Director/PDMR Shareholding

GlaxoSmithKline PLC
20 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 Slaoui, a Person
Discharging Managerial Responsibility, in the American Depositary Shares (ADSs)
of GlaxoSmithKline plc (the "Company") following transactions in the shares of a
connected person, as follows:



On 19 February 2008, Dr Slaoui's connected person, who is also an employee of
the Company, received the following awards:


Award under                                                ADSs
GlaxoSmithKline Performance Share Plan                    1,570
GlaxoSmithKline Share Option Plan                         3,570
GlaxoSmithKline Share Value Plan                            890



The award of share options was made at a subscription price of $44.75 per ADS.



The vesting of the Performance Share Plan award is subject in part to
GlaxoSmithKline's TSR performance, and in part to the growth in the Company's
earnings per share over the performance period from 1 January 2008 to 31
December 2010 (the "Performance Period").



The vesting of the GlaxoSmithKline Share Value Plan is subject to continued
employment.



The Company and Dr Slaoui's connected person were advised of these transactions
on 20 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



20 February 2008


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