A total of 961 patients underwent coronary artery bypass grafting (CABG) between 1982 and 1991, and we investigated perioperative cerebral infarction. The average age of operation in these case was 65±4 years. There was 9 patients with hypertension, 7 with diabetes mellitus and 5 with hyperlipidemia. Concerning cerebral infarction, there were 3 patients with multiple infarction, 6 with infarction of the mid cerebral artery area, 1 with infarction of posterior cerebral artery area, 1 with infarction of posterior cerebral artery area, 1 with infarction of pons and 1 with infarction of the ophthalmic artery. The courses of infarction involved atherosclerosis, hypoperfusion during cardiopulmonary bypass, thrombosis due to arterial fibrillation and thrombus on the left ventricular wall. Three patients who had critical cerebral infarction died after CABG. We consider that avoid perioperative cerebral infarction preoperative atherosclerosis, thrombus and to choose the proper procedure of the operation.