Since 1973, 40 patients with Patent Ductus Arteriosus were operated in The Department of Thoracic and Cardiovascular Surgery, Korea University Medical College. Clinical analysis of these cases: 1. Age ranged from 8 months old to 28 years old Sex ratio was 22 females to 18 males. 2. Pulse pressure widening above 50 mmHg was appeared in 27 patients. In 31 patients, continuous machinery murmur was heard on left second and third intercostal space, but 9 patients has holosystolic murmur on left sternal border. 3. Retrograde Aortography was performed in 11 patients and right heart catheterization, 17 patients, In 8 patients, pulmonary hypertension [above 30 mmHg in` systole] was noted. 3 out of 8 patients was combined with Ventricular Septal Defect. Severe pulmonary hypertension [above 80mmHg in systole] was presented in 3 patients. 4. In 38 patients, operative method was performed with multiple suture ligation of PDA, and in 2 patients, suture closure through pulmonary arteriotomy under cardiopulmonary bypass. 5. One operative death occurred in a patient in this group. Cause of death was right heart failure after multiple suture ligation of PDA and pulmonary artery bandings.[KTCS 1979;2:105-109]