Since the first report of successful ligation of patent ductus arteriosus in 1939, it`s surgical intervention has become a routine and relatively safe procedure. During the past ten years from Aug. 1975 to Aug. 1985, 107 cases were operated on for a patent ductus arteriosus at the Department of thoracic and Cardiovascular Surgery, School of Medicine, Kyungpook National University. Clinical analysis of these cases was performed. Mean age at operation was 9.4 years, ranging from 20 months to 32 years. Sex ratio of female to male was 1.8;1. Most common symptoms were frequent respiratory infection, exertional dyspnea, and palpitation. Diagnosis was made by auscultation, 2 dimensional echocardiography, cardiac catheterization, and cineangiocardiography. A moderate to severe pulmonary hypertension was found in 42 cases [49.4%] in cardiac catheterization. Operative methods were multiple ligation of paten`. ductus arteriosus with or without Dacron or Teflon wrapping in 72 cases [68%], and division and suture in 34 cases [32%]. There were three operative deaths [2.8%]. The causes of death were hemorrhage from tearing of aorta, low cardiac output, and arrhythmia. All of these cases had moderate degree of pulmonary hypertension.