A retrospective analysis of 12-year experience with open heart surgery in 74 patients 70 years of age and older during 1979 and 1990 was performed. The subjects consisted of 51 patients with coronary artery disease, 11 with acquired valvular disease, 2 with congenital heart disease and 10 with combined heart disease. Operative mortality was 9% and late mortality, 16%. The incidence of low output syndrome and respiratory failure were significantly high postoperatively. Multivariate analysis demonstrated that determinants of operative prognosis were postinfarction ventricular septal perforation, aortic cross-clamp time, preoperative renal dysfunction and coronary-valvular combined disease. Actuarial survival rate at 5 years was 89% for an entire series, which was favorably compared with age-sex matched population.