Among the 628 consecutive patients who underwent coronary bypasses performed by the same surgical group between January 1, 1982 and December 31, 1987, 71 (11 p. 100) were aged 70 years or more (mean: 72.5 years; range: 70-83 years). 99 p. 100 of the patients had a history of severe, disabling exertional angina (46 p. 100) or unstable angina (52 p. 100) of 55 months' duration on average; 35 patients (49 p. 100) had already experienced myocardial infarction. Coronary angiography showed a one-vessel disease in 1 case, a two-vessel disease in 1 case, a two-vessel disease in 31 cases and a three-vessel disease in 39 cases; 11 patients (15 p. 100) had stenosis of the left main coronary artery. The ventricular function was considered unaltered in 59 cases (83 p. 100). Altogether, 155 bypasses, including 25 internal mammary grafts, were performed, i.e. an average of 2.2 bypasses per patient. There was only one early (21st day) post-operative death. The post-operative period was uneventful in 57 patients (60 p. 100); 9 developed peri-operative necrosis. Seventy patients have been followed up for a mean period of 24 months: there were 3 late deaths of non-cardiac origin; 60 patients (84.5 p. 100) are now asymptomatic and 3 (4.5 p. 100) are suffering from residual angina. Early mortality excluded, the cumulative probability of survival at 5 years is 94 p. 100.(ABSTRACT TRUNCATED AT 250 WORDS)