From March 1977 to November 1988, 99 patients were reoperated on after a first valvular replacement. Mean delay between the two operations was 53 months (10 days to 18 years). The patients were reoperated on mainly for mechanical disinsertion (30), bacterial endocarditis (25) and thrombosis (18 patients). Operative mortality was 11%, mainly following reoperation for bacterial endocarditis. Mean follow-up (85 patients) was 49 months (6 months-11 years). 75% were alive and doing well 4 years after reoperation and 66% at 6 years. Eight patients needed a third operation with two deaths.