Thrombolytic therapy in acute ischemic stroke is safe and effective in a defined subgroup of stroke patients. Until now, different fibrinolytic substances including urokinase, streptokinase and recombinant tissue plasminogen activator (rt-PA) have been tested regarding safety, efficacy, dosage and economic parameters in patients suffering from both carotid and basilar artery territory strokes. Recently, two large multicenter placebo-controlled intravenous rt-PA studies were published. The results show that thrombolysis of acute carotid territory strokes (European Cooperative Acute Stroke Study) and of strokes with a deficit measurable on the NIH Stroke Scale (National Institute of Neurological Disorders and Stroke rt-PA Stroke Study) improves clinical and economic outcome parameters in patients who were treated within 6 hours of the onset of symptoms and had that no signs of extended early infarction on the initial CT-scan. The occurrence of intracranial hemorrhages is more frequent after thombolytic therapy, but the majority of bleeding complications referred to petechial or more confluent hemorrhage limited to the infarcted tissue, without clinical deterioration. However, the identification of the appropriate patients is difficult and depends on the level of clinical and diagnostic experience. In vertebrobasilar artery territory stroke, local intraarterial thrombolysis with urokinase or streptokinase is performed in most cases. Thrombolytic treatment within twelve hours of the onset of symptoms was associated with significantly better results concerning both survival and neurological recovery.