ABSTRACTWe have assessed the long-term results of coronary bypass surgery for angina from 1974 to 1983 in 1304 patients aged 65 years and older (group 1). Using actuarial techniques, we determined that the 5 year and 10 year survival rates for patients 65 years old or older were 81 + 2% and 65 + 3% (mean + SE), respectively. The patients aged 65 years and older were further subdivided into those aged 65 to 74 years (group la) and 75 to 84 years (group lb) and were compared with 1700 patients aged 55 to 64 years (group 2). The operative mortality in the three subgroups was 3%, 3%, and 2%, respectively (p = NS). For coronary bypass surgery, the duration of hospital stay was significantly longer (p < .0001) by a mean of 1 to 2 days for group 1 patients and the cost of hospitalization was higher by a mean of ±700 (p = .25). The cost of hospitalization was significantly higher only for group lb patients (p = .005). The 5 year survival rates for the three subgroups (la, lb, and 2) were 83 + 2%, 73 ± 5%, and 91 + 1%, respectively, and the 10 year survival rates were 66 + 3%, 65 + 7% (7 year rate for subgroup lb), and 77 2%, respectively. The lower survival rates for subgroups la and lb were significant (p < .001); however, this lower survival was only seen in men. The mortality in the general population is expected to be higher for men than for women and for patients over 65 years old (expected mortality). For men, the mortality observed in our patients was lower than the expected mortality by a similar margin for all three subgroups. This suggests that the observed higher mortality of men in subgroups la and lb is at least partly related to their older age. The reoperation rates (p = .72) and angina status at 1 to 5 years (p = .08) and 6 to 10 years (p = .68) were not significantly different among the three subgroups. We conclude the immediate and long-term results of coronary bypass surgery in patients aged 65 to 84 years are similar to those seen in a younger patient group. Therefore coronary bypass surgery should be offered to the older members of our society for the usual indications.