With increasingly elderly patients and also increasing numbers of patients with ischemic heart disease, the number of cases requiring coronary artery bypass grafting (CABG) combined with aortic valve surgery has recently been steadily increasing. In addition, the management of asymptomatic aortic valve diseases at the time of CABG still remains controversial. The purpose of this study was to evaluate the early and late prognoses of patients undergoing a simultaneous aortic valve replacement (AVR) and CABG. Between January 1988 and December 1997, 17 patients underwent AVR and CABG. According to the pressure gradient, the patients were divided into four groups: five with aortic regurgitation (AR), two with mild aortic stenosis (AS), six with moderate AS and four with severe AS. The mean number of distal coronary anastomoses was 1.8 and a mechanical prosthesis was used in all cases. Hospital death occurred in one case with severe AS. The postoperative complications consisted of one mild AS case with transient complete atrio-ventricular block, two cases with a new cerebral infarction, one case with loss of consciousness, one moderate AS case with perioperative myocardial infarction, and one each of severe AS with, respectively, multiple organ failure, congestive heart failure (CHF) and acute renal failure. In addition, three valve-related complications were also observed. Late death occurred in two cases: one due to a cerebrovascular accident and one due to CHF. Both the early and late outcomes of the patients undergoing the above described simultaneous operation were satisfactory, suggesting that this combined operation is therefore considered to be an effective surgical modality for the treatment of ischemic heart disease patients.