Three hundred and sixty seven cases of open heart surgery were done in the Department of Thoracic and Cardiovascular Surgery, Pusan National University Hospital from July, 1981 to October, 1985. 1. The age distribution of congenital heart disease patients was 3 to 41 years old and mean age was 12.7 years and of acquired heart disease was 9 to 57 years old and mean age was 30.9 years. 2. There were 281 cases [64.9%] of acyanotic congenital heart anomalies, 43 cases [11.7%] of cyanotic anomalies and 86 cases [23.4%] of acquired heart disease. 3. For myocardial protection, Bretschneider and potassium glucose solution had been used as cardioplegic solution but recently GIK solution is being used as secondary cardioplegic method by infusing repeatedly every 30 to 40 minutes time interval with excellent results. 4. The overall mortality was 8.2%. And the mortality rate in each disease entity is 2.5% in congenital acyanotic cases, 32.6% in congenital cyanotic cases and 11.6% in acquired valvular disease.