From January 1985 to December 1992, of 1257 patients who underwent a heart valve replacement 210 [16.8% underwent reoperation on prosthetic heart valves, and 6 of them had a second valve reoperation. The indications for reoperation were structural deterioration [176 cases, 81.5% , prosthetic valve endocarditis [25 cases, 11.6% , paravalvular leak [12 cases, 5.6% , valve thrombosis [2 cases, 0.9% and ascending aortic aneurysm [1 case, 0.4% . Prosthetic valve failure developed most frequently in mitral position [57.9% and prosthetic valve endocarditis and paravalvular leak developed significantly in the aortic valve [40%, 75% [P<0.02 . Mean intervals between the primary valve operation and reoperation were 105.3$pm$28.4 months in the case of prosthetic valve failure, 61.5$pm$38.5 months in prosthetic valve endocarditis, 26.8$pm$31.2 months in paravalvualr leak, and 25.0$pm$7.0 months in valve thrombosis. In bioprostheses, the intervals were in 102.0$pm$23.9 months in the aortic valve, and 103.6$pm$30.8 months in the mitral valve. The overall hospital mortality rate was 7.9% [17/26 : 15% in aortic valve reoperation [6/40 , 6.5% in reoperation on the mitral prostheses [9/135 and 5.7% in multiple valve replacement [2.35 . Low cardiac output syndrome was the most common cause of death [70.6% . Advanced New York Heart Association class [P=0.00298 , explant period [P=0.0031 , aortic cross-clamp time [P=0.0070 , prosthetic valve endocarditis [P=0.0101 , paravalvularr leak [P=0.0096 , and second reoperation [P=0.00036 were the independent risk factors, but age, sex, valve position and multiple valve replacement did not have any influence on operative mortality. Mean follow up period was 38.6$pm$24.5 months and total patient follow up period was 633.3 patient year. Actuarial survival at 8 year was 97.3$pm$3.0% and 5 year event-free survival was 80.0$pm$13.7%. The surgical risk of reoperation on heart valve prostheses in the advanced NYHA class patients is higher, so reoperation before severe hemodynamic impairment occurs is recommended.