In September 2002 the European Medicines Evaluation Agency (EMEA) approved a licence for alteplase (rt-PA) in the treatment of ischaemic stroke within 3 h of symptom onset. One of the conditions required by the EU regulatory authorities for the official definitive approval of thrombolytic therapy was that treatment safety should be monitored over a period of three years by entering all treated patients in the SITS-ISTR (Safe Implementation of Thrombolysis in Stroke -Thrombolysis Register) web register, in accordance with a study protocol, the SITS Monitoring Study - SITS-MOST. The aims of this study are to evaluate the efficacy (in terms of functional independence for activities of daily living at three months after treatment) and safety (in terms of symptomatic intracerebral haemorrhage and death) of the thrombolytic treatment in real routine clinical practice, outside the ideal conditions of an experimental setting, and to compare the results with a systematic review from the randomised clinical trials.