We determined the outcome of coronary artery bypass surgery in 500 consecutive patients followed for at least 10 years after operation. There were 446 males (89.2%). Angina pectoris was the major indication for operation. Four hundred six patients (81%) had multivessel coronary artery disease and 348 (69.9%) had good left ventricular function. At 10 years of follow-up, 48% of patients were asymptomatic and 41% were improved. Propranolol was being used by 36% of patients and nitrates by 49%. Of the 355 patients younger than 65 years of age at the time of follow-up, 57% were employed full time and 24% were working part-time. Reoperation was performed in 9% of patients. Analysis of survival by Kaplan-Meier curves indicated that overall 10-year survival rates were 78% for one-vessel disease, 69% for two-vessel disease, 48% for three-vessel disease and 67% for left main coronary artery disease. For patients with good left ventricular function, the 10-year survival rates were 83% for one-vessel disease, 73% for two-vessel disease, 53% for three-vessel disease and 73% for left main disease. For patients with poor left ventricular function, the rates were 56%, 59%, 40% and 54%, respectively. Cox multivariate analysis indicated that preoperative diuretic use, history of heart failure, the number of diseased vessels, and infarct on the preoperative ECG were all good predictors of survival. This study shows that the outcome of coronary artery bypass surgery 10 years operation is highly favorable.