Intravenous recombinant tissue-type plasminogen activator is approved by the US Food and Drug Administration for treating acute ischemic stroke within 3 hours of onset of symptoms. Initiation of thrombolysis within 90 minutes of onset of symptoms is a treatment goal supported by current studies. Postmarketing data suggest that the risk of intracranial hemorrhage may be unacceptably high when recombinant tissue-type plasminogen activator is given to patients who would not have been eligible for enrollment in the pivotal phase 3 clinical trials. Further studies of local intra-arterial thrombolysis and improved selection of patients with advanced brain imaging are expected in the future, but the emphasis at present should be on rapid identification, evaluation, and treatment of appropriate patients with intravenous therapy.