Data from 1,156 patients greater than or equal to 30 years of age who underwent aortic valve replacement alone or with coronary artery bypass grafting from 1967 through 1976 (early series) and 227 similar patients operated on during 1982 and 1983 (late series) were reviewed. In the early series, 414 patients (36%) had preoperative coronary arteriography (group 1): group 1A (n = 224) did not have coronary artery disease, group 1B (n = 78) had coronary artery disease but did not undergo bypass grafting and group 1C (n = 112) had coronary artery disease and underwent bypass grafting. The 742 patients in group 2 did not have preoperative arteriography. Operative mortality rates (30 day) in groups 1A, 1B, 1C and 2 were 4.5, 10.3, 6.3 and 6.3%, respectively (p = NS). The 10 year survival in both groups 1 and 2 was 54%; in groups 1A, 1B and 1C it was 63, 36 and 49%, respectively (1A and 1B, p less than 0.01). In the late series, the 227 patients were divided into similar groups (group 1A, n = 73; 1B, n = 32; 1C, n = 99), and 90% had preoperative coronary arteriography. Operative mortality rates (30 day) for groups 1A, 1B and 1C were 1.4, 9.4 and 4.0%, respectively; that for group 2 (no preoperative arteriography, n = 23) was 4.3%. Definition of coronary anatomy by angiography seems important in most patients greater than or equal to 50 years old who are candidates for aortic valve replacement, and bypass grafting is recommended for those with significant coronary artery disease.