SummaryEmergency treatment of acute thromboembolic stroke by lysis of the occlusive arterial clot has received increasing attention in recent years. Development of newer thrombolytic agents combined with an enhanced appreciation of the time course of reversible cerebral ischemia have led to further clinical and laboratory exploration of this approach to stroke treatment, which had previously been believed to be unsafe. Recent studies suggest that very early recanalization of cerebral arteries can be achieved with acceptable risks using either local arterial or intravenously administered thrombolytic agents. While most published reports have suggested clinical benefit, definitive proof of sustained clinical efficacy, as measured by overall functional outcome and compared to concurrent controls, remains to be established.