Between 1976 and 1982 four hundred consecutive patients underwent coronary artery bypass surgery and were operated by the same surgical team: 345 men (88.5%) and 46 women (11.5%). The average age was 56 years (7.5% were over 75 years of age); 86% of patients were infunctional classes III and IV; 46% had triple vessel disease and 9.25% had severe stenosis of the left main stem. Left ventricular ejection fractions were decreased in 26% and very poor in 4.5% of patients. The average number of bypass grafts was 1.72 per patient and the operative mortality was 3.5%. The 10 year survival rate was 81% and 75% of these patients still thought that their condition had been improved by surgery although only 30% were completely asymptomatic and had had no further coronary event. A comparison with a control population of the same age showed better survival in the surgical group in patients surviving operation. Contrary to traditional thinking, the surgical patients suffered relatively few deaths of cardiac causes but as many, if not more, of cancer. The operated patients died of approximately the same diseases as the control population of the same age but in lower proportions for each cause of death (17 cardiovascular deaths in the control population compared with 13 in the operated group; 18 versus 10 deaths of cancer, and 18 versus 8 deaths of other causes in the control and operated patients, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)