From 1958 to October 1977, 294 cases of acquired heart disease were operated. There were 68 cases of pericardium, 3 trauma, 2 foreign body, one cardiac thrombus, 3 atrial myxoma, 2 left atrial and 1 right atrial, 2 Budd-Chiari syndrome, and 214 valvular heart disease. Out of 214 cases of valve operation 73 valves were replaced in 64 patients. Male to female ratio was 1.46: 1. The youngest age was 14 years in male and 18 in female. The oldest was 54 years in male and 52 in female. Fifty-five cases of single valve were replaced, consisting of 47 mitral and 8 aortic valves. `There were 9 double valve replacement cases which consist of 7 mitral and aortic and 2 mitral .and tricuspid valves. Six varieties of prosthetic valves, 3 ball and 3 disc types and 3 kinds of xenograft tissue valves were utilized. Beall, BjSrk-Shiley and Starr-Edwards prosthetic valves and Hancock valves were used mainly. For single valve 34. 5% and for double valve replacement 44% mortality were noted. There were 23 operative deaths out of 64 patients, over all mortality rate of 36.9%. Mortality for mitral valve replacement was 29.5%. But in recent 12 consecutive cases one death occurred, showing 8.3% mortality. In earlier days thrombocyte anti-adhesive drug dipyramidole-persantin-aspirin and/or SP 54 were adminstered. But in recent cases after heparinization, coumadin and Persantin were prescribed routinely.[KTCS 1977;2:315-326]