Sixty cases of open heart surgery were performed in the Department of Thoracic and Cardiovascular Surgery of Chonbuk National University Hospital from July, 1983 to June, 1984. The patients were consisted of 40 [66%] congenital anomalies containing 26 [43%] patients of acyanotic group and 4 [23%] of cyanotic group, and 20 [34%] acquired heart diseases which involved one or more cardiac valves. The male patients were 42 and the female 18. In 20 valvular heart diseases, open mitral commissurotomy was done in 5 patients, mitral valvular replacement with tissue valve in 6, mitral valvular replacement with mechanical valve in 5, mitral valvular replacement with tricuspid annuloplasty in 2, mitral annuloplasty in 1, and mitral and aortic valvular replacements with mechanical valves in 1. The most frequency complication was low cardiac output syndrome occurred in 9, and the next was urethral stenosis, ARDS, and postoperative bleeding, etc. The perioperative mortality was 21% in congenital cyanotic heart disease, 12% in congenital acyanotic heart disease, and 5% in acquired heart disease.