A 76-year-old man was admitted with a diagnosis of mitral valve regurgitation and angina pectoris. Cardiac catheterization demonstrated grade III mitral valve regurgitation with elevated pulmonary pressure and stenosis in the LAD. Severe stenosis in the left internal carotid artery and multiple cerebral infarctions were also recognized. Mitral valve repair with coronary artery bypass was performed at one month after the left carotid endarterectomy. The ascending aorta contained fragile atheroma, so an arterial cannula was inserted into the graft anastomosed to the right axillary artery. Mitral valve repair with coronary artery bypass was performed under moderately hypothermic ventricular fibrillation. Air embolism in the right coronary artery was recognized during systemic rewarming. Mitral valve repair with coronary artery bypass was performed safely under moderately hypothermic ventricular fibrillation in this case of an atherosclerotic ascending aorta. Axillary artery cannulation is useful to avoid cerebral complications in such cases. The de-airing procedure should be completed before the initiation of the heart beating.