Between 1965 and 1984, 109 patients underwent simultaneous aortic and mitral valve replacement and tricuspid valve repair at the Mayo Clinic, with a perioperative mortality of 21%. The only variable predictive of perioperative mortality on multiple regression analysis was New York Heart Association class IV disability. The median follow-up was 5.6 years (range 1 to 20 years). Cumulative 5-, 10-, and 15-year survival rates in patients discharged from the hospital were 70% +/- 5%, 42% +/- 6%, and 33% +/- 7%. Multivariate analysis identified advanced age and class IV disability as significant predictors of poor survival. Five-year survival rates were similar in patients undergoing operation between 1965 and 1974 and after 1975, despite an increase in age and in the severity of preoperative symptoms in the recent group. Late mortality was due to sudden death in 38% of the patients, heart failure in 21%, reoperation in 5%, endocarditis in 2%, and thromboembolism and bleeding in 4%. Late complications included systemic emboli in 22% (embolism rate 4.5 events/100 patient-years), bleeding in 17%, reoperation in 14%, myocardial infarction in 8%, permanent pacemaker implantation in 5%, and infective endocarditis in 3%. Of 43% of the patients still alive, 79% are in class I or II.