Intracerebral hematoma (ICH) after reperfusion procedure in cerebral ischemia is a rare but serious complication. The authors present 4 cases with ICH after reperfusion procedures in cerebral ischemia. First case is ICH after superficial temporal artery-middle cerebral artery anastomosis in moyamoya patient, second case is ICH after graft bypass usuing saphenous vein in traumatic carotid artery injury patient, third case is ICH after intra-arterial urokinase therapy in acute internal carotid artery occlusion and forth case is ICH after temporary clipping to the middle cerebral artery in middle cerebral artery aneurysm surgery. Defective cerebrovascular autoregulation in ischemic brain regions may predispose patients to ICH after reperfusion procedure in cerebral ischemia. The authors suggest reperfusion procedure in ischemia must be executed prudently because of possibility of reperfusion injury including ICH.