During one year[1987], 110 cases of open heart surgeries were performed in the department of Thoracic and Cardiovascular Surgery, Pusan Paik Hospital, Inje Medical College. And the results were summarized as follows. 1. Among the 110 cases, there were 77 cases of congenital heart diseases and 33 cases of acquired heart diseases. Age range of the congenital patients was 8 months to 30 years with the mean age of 8 years, and acquired patients was 16 to 56 years with the mean age was 32 years. 2. The heart lung machine used for cardiopulmonary bypass was Sarns 7000, 5-head roller pump, and the number and type of oxygenators were 50 of membrane type and 60 of bubble type. For all cases GIK[glucose-insulin-potassium] solution was used as cardioplegic solution for myocardial protection during operation. 3. Among the 77 congenital anomalies, there were 67 cases of acyanotic patients[ASD: 12, VSD: 50, PS: 1, AP window: 1, Gerbode defect: 1, ECD: 2] and 10 cases of cyanotic patients[TOF: 10], and to all of which the appropriate radical operations were applied. 4. Among the 33 acquired diseases, there were one case of left atrial myxoma, one of annuloaortic ectasia, 20 of mitral valve diseases[MS: 2, MSr: 8, MR: 2, MRs: 8], 9 of double valve diseases[MRs+AR: 1, MRs+ARs: 2, MRs+TR: 1, MSr+TR: 3, MSr+ASr: 1, MSr+ARs: 1], 2 of triple valve diseases[MSr+AR+TR: 1, MSr+ASr+TR: 1]. The left atrial myxoma was removed well with right atriotomy and atrial septal approach. And to the annuloaortic ectasia, Bentall operation was applied with good result. Mitral valve replacement[MVR] was applied to 20 cases of mitral valve diseases, double valve replacement[MVR+AVR] was applied to 6 cases of double valve diseases, MVR & tricuspid annuloplasty[TVA] was applied to 3 cases of mitral 5. The number of replaced valve were 39 in 31 cases. In MVR, 5 of mechanical valves[St. Jude Medical Valve] and 26 of tissue valves[Carpentier-Edward valve] were used. In AVR, 3 of mechanical valves and 5 of tissue valves were used. 6. Postoperative complications were occurred in 23 cases, and among them 21 cases were recovered with intensive cares, but 2 cases were expired[mortality: 1.8%].