Perioperative cerebral infarction occurs in less than 1% of general surgical procedures; the mechanism is usually unknown. The clinical features of 12 consecutive perioperative strokes were retrospectively reviewed. Although intraoperative hypotension was frequent, onset of deficit occurred postoperatively in 83% and intraoperatively in 17%. Cardiogenic embolism was a common cause of stroke (42%), with atrial fibrillation present in 4 patients (33%) at the time of stroke. The potential roles of hypercoagulability, hypotension and carotid occlusive disease are discussed. Future reports concerning perioperative stroke should consider the multiple mechanisms and temporal relationship of stroke to the operative procedure.