From January 1985 to July 1985, prosthetic heart valves were replaced in 5 patients at Keimyung University Dongsan Medical Center. The patients included three women and two men ranging in age from 22 to 41 years. Three mitral valve replacements, one aortic valve replacement and one double valve replacement [mitral and aortic valve replacement] were done at the first valve operations. Reoperation were performed 2 to 76 months after the first operations, Prosthetic valve endocarditis occurred in 3 patients, early in one and late in two and primary valve failure occurred in 2 patients. In operative findings, vegetation in prosthetic valve endocarditis and calcification in primary valve failure were found. All except one had relatively successful operative results. One died of early fungal prosthetic valve endocarditis due to relapsed prosthetic valve endocarditis with heart failure and block.