Intravenous thrombolysis with tPA is the only approved and effective treatment for acute ischemic stroke. The approval, however, is restricted to treatment within 3 hours of stroke onset, and it is not recommended to treat patients beyond 80 years of age. Due to these restrictions, thrombolysis is only given to a small number of acute stroke patients. At the same time there is growing evidence that patients can be treated with thrombolysis safely and effectively even beyond these restrictions. We give an overview over the published data regarding thrombolysis beyond the 3 hour time window and in patients aged 80 or over. Based on these data we conclude that (1.) intravenous thrombolysis in MRI selected patients is safe and effective within an extended time window of up to 6 hours, and (2.) there is no increase in mortality or symptomatic intracerebral bleeding complications in patients aged 80 or over treated with thrombolysis. A great number of acute stroke patients reaches the hospital beyond the 3 hour time window, and there is a growing number of old and very old stroke patients in the western world. Treating patients up to a 6 hour time window and beyond the age of 80 years would clearly increase the number of patients, which might benefit from this effective treatment. To summarize, we recommend experienced stroke centres to treat acute stroke patients with thrombolysis up to 6 hours using MRI criteria for patient selection, and to treat also patients aged 80 years or older.