During a 33-month period ending June, 1972, 1,492 patients underwent aortocoronary saphenous vein bypass (ACB). The early mortality with ACB alone was 7.1%, while mortality was more than double (14 of 86 patients died) when ACB was combined with resection or plication of a ventricular aneurysm. Twenty of 84 patients died in the early period following combined ACB and valve resection. One patient among 8 who had concomitant resection of an ascending aortic aneurysm died after operation. Factors that increased mortality in this series were advanced age, female sex, high coronary artery scores, left main coronary artery lesions, high left ventricular end-diastolic pressure, left ventricular dysfunction, congestive heart failure, the requirement for endarterectomy to perform the anastomosis, and recent acute myocardial infarction. Actuarial data from patients who underwent ACB without concomitant procedures show an annual attrition rate of 2.7% per year, which compares to rates of 4, 6, and 10% for patients with single, double, and triple coronary disease treated without operation. In 311 men and women under the age of 70 who had a coronary artery score below 13 and none of the other risk factors, the early mortality was 1.6% (5 patients) and the late mortality was 1.0% (3 patients).