Director/PDMR Shareholding

GlaxoSmithKline PLC
20 February 2008



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


The Administrators of the GlaxoSmithKline Performance Share Plan notified the
Company and the under-mentioned persons on 19 February 2008 of an increase in
their notional interests in Ordinary shares at a price of £11.04 per share and
Ordinary Share ADRs at a price of $43.66 per ADR following the notional
re-investment of the dividend to which shareholders entered on the register of
members at the close of business on 15 February 2008 are entitled to receive.


                                                      Ordinary shares                    ADRs
Dr J-P Garnier*                                                                     10,082.53
Mr A P Witty*                                                3,688.75
Mr R M Bondy                                                 3,569.48
Mr J M Clarke                                                2,760.79
Mr M Dunoyer                                                 1,344.35
Mr E J Gray                                                    547.01
Mr J S Heslop*                                               3,354.38
Mr D Learmouth                                                 491.97
Dr M Slaoui*                                                   599.07                1,019.65
Dr R G Greig                                                                         1,148.27
Mr W C Louv                                                                            532.06
Mr D J Phelan                                                                        1,768.34
Dr D Pulman                                                                          1,148.27
Mr D M Stout                                                                         4,212.02
Mr C Viehbacher*                                                                     1,827.45

* denotes the individual is an Executive Director

Dr Slaoui's connected person, who is also an employee of the Company, also
received 52.17 Ordinary shares and 23.20 ADRs following the notional
reinvestment of the aforementioned dividend.



The notional dividends accrued will be paid out in proportion to the percentage
of participants' Performance Share Plan holdings that vest following the end of
the relevant three year measurement period.



This notification relates to transactions 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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