Moyamoya disease is the result of progressive steno-occlusive changes in the internal carotid arteries followed by formation of bilateral abnormal vascular networks. The disease may present with cerebral ischemia causing cerebral hemorrhage in the perioperative period. There are few reports of cardiac surgeries in patients with moyamoya disease, and the management during cardiopulmonary bypass for moyamoya disease has not been established. We gave general anesthesia for mitral valve plasty in patient with the moyamoya disease. A 52-year-old woman underwent mitral valve plasty. She had been diagnosed with moyamoya disease and during the cardiopulmonary bypass, we used alpha-stat blood gas management with mild hypothermia, and maintained PaCO2 around 40 mmHg. We maintained the perfusion flow of CPB above 3.0 l x min(-1) x m(-2) and the mean perfusion pressure above 70 mmHg. In addition, we used the pulsatile perfusion assist with intraaortic balloon pumping to maintain cerebral circulation. Postoperative course was uneventful without apparent neurologic deficit, and she was discharged from hospital on 10th postoperative day.