Recently percutaneous transluminal coronary recanalization therapy (PTCR) with urokinase infusion has became one of popular technique for coronary arterial occlusion. This paper reported clinical experience of intraarterial urokinase infusion therapy for acute or superacute stroke patients. The procedure was followed by angiographical study which revealed the major intracerebral arterial occlusion in three cases. Case 1: A 74-year-old female had sudden onset of clouding of consciousness with complete left hemiplegia. The patient was in our urological ward because of treatment for her right ureter tumor, as the patient was immediately subjected to angiographical study and complete occlusion of the trunk of the right middle cerebral artery was revealed four hours after onset. Successively 240,000 IU of urokinase solution was injected through the arterial catheter after angiographical study. This procedure repeated two times with 10 minute intervals. So total amount of 720,000 IU of urokinase was given by intraarterial injection. Immediately after the last urokinase injection the patient started to recover her consciousness and weakness. Simultaneous angiogram demonstrated partial recanalization of the proximal branches of the middle cerebral artery. The following day, she had complete recovery from her neurological deficits although she had transient hemorrhagic tendency. The final angiogram showed no existence of obstructed cerebral arteries as well as no low density areas in computed tomographic images. Case 2: A 73-year-old female, with the left internal carotid occlusion at the site of C1-2 portion, was instituted infusion therapy of similar procedure with total amount of 960,000 IU oi urokinase ten to twenty hours after onset. However, no rewarding was obtained.(ABSTRACT TRUNCATED AT 250 WORDS)