A clinical study on 139 cases of operated PDA was performed during period from Aug. 1982 to Apr. 1991 at the Dept. of Thoracic and Cardiovascular Surgery of Chonbuk National University Hospital. The following results are obtained. 1. The 35 males and 104 females ranged in age from 6 months to 40 years. [mean 10.2 yrs. ] 2. Chief complaints of the patients were frequent URI in 50%, dyspnea on exertion in 31.2%, palpitation in 11.1%, and no subjective symptoms in 28.78% 3. On auscultation, continuous machinery murmur heard in 79.86% and systolic murmur in 20.14%. 4. Radiologic findings of chest P-A showed increased density of pulmonary vascularity in 80.58%, cardiomegaly in 61.87%, and within normal limit in 19.42% of the patients. 5. The signs of LVH[44.4%], RVH[17.4%], BVH[7.6%] were noted on the EKC. 6. Cardiac catheterizations were performed in 114 patients. The mean Qp/Qs was 2.65 and the mean Pp /Ps was 0.41 and the mean systolic pulmonary artery pressure was 46.6 mmHg. 7. Operative methods were as followed: The 130 cases[93.52%] of ligation and 3 cases[2.16%] of division & suture for PDA were performed through the left posterolateral thoracotomy. And the remained cases were managed under the cardiopulmonary bypass. 8. Operative complications were hoarseness in 8 cases, atelectasis in 6 cases, intraoperative ductal rupture under the left thoracotomy approach 2 cases, recannalization 1 case and others in 3 cases. 9. One patient died due to ductal rupture intraoperatively and the overall mortality was 0.7%.