103 cases of open heart surgery were performed in the Department of Thoracic and Cardiovascular Surgery, Kyungpook National University Hospital in 1984. There were 90 congenital cardiac anomaly and 13 acquired heart diseases. Out of 90 congenital cardiac anomaly, 63 cases of acyanotic group and 27 cases of cyanotic group were noted. In 63 cases of acyanotic group, 11 ASD, 45 VSD and 7 other acyanotic anomaly were included. In 27 cases of cyanotic group, 4 Trilogy of Fallot, 15 TOF, 3 Pentalogy of Gasul and 5 other cyanotic anomaly were found. Among 13 cases of acquired heart diseases, 12 valvular lesions and 1 atrial myxoma were noted. Two open mitral commissurotomy and ten valve replacements were performed for 12 valve lesions. The frequent complications were acute respiratory insufficiency and low cardiac output syndrome occurred in 5 cases. The perioperative mortality was 4.8% in acyanotic congenital cardiac anomaly, 7.4% in cyanotic congenital cardiac anomaly, and 0% in acquired heart diseases. Overall mortality for 103 cases of open heart surgery was 4.9%.