PURPOSE: To evlauate the efficacy of direct intracranial intraarterial thrombolytic therapy in patients withacute atherothrombotic and embolic stoke. MATERIALS AND METHODS: Forty-one patients with cerebral thromboembolic disease, all in the area of the middle cerebral artery and including two cases of internal carotid artryocclusion, were treated with microcatheter-directed local intraarterial thrombolysis, using 180,000 to 1,000,000unit urokinase and 15 to 50mg of tissue plasminogen activator (tPA). The time elapsed before treatment ranged from260 to 470 minute (mean : 380 minutes). The effect of treatment was assessed by cerebral angiography, by CT and bythe clinical outcome. RESULTS: For 25 patients (61%), complete vessel recanalization was successful, In eightand three cases, respectively, the result was partial recanalization and residual stenosis. In 21 patients (51%),both acute neurologic and functional outcomes improved significantly within 24 hours and in 92% of patients, within one month. Hemorrhagic transformations occured in five patients (12.2%), and in five others there were high density lesions around the basal ganglia and temporal lobe, which was cleared on CT within 24 hours This suggested transient extravasation of the contrast media rather than true hemorrhage. tPA showed better results than urokinase in terms of the rate of recanlization (68.7% vs 56.7%) and the occurrence of hemorrhagic infarction(6.3%vs 16.9%). CONCLUSIONS: Local intraarterial cerebral thrombolysis is thought be an effective method in the treatment of acute brain infarction, but in some patients may cause intracerebral hemorrhage in some patients.