A clinical analysis was performed on 115 cases of -patent ductus arteriosus treated surgically during the period of 11 years from Aug. 1977 to Jul. 1988. at the Department of Thoracic and Cardiovascular Surgery, Chungnam National University Hospital. Among 115 cases, male was 38 and female was 77 and ages ranged 12 days to 27 years old with the average of 8 7/12 years. The major clinical symptoms on admission were frequent URI attack[77.4%], dyspnea on exertion[32.2%] and palpitation[13%]. On auscultation, continuous machinery murmurs were detected in 97 cases[84.3%] and loud systolic murmurs were detected in 18 cases[15.7%]. Preoperative electrocardiographic findings were as follows: LVH 59[51.3%], RVH 12[10.4%], BVH 16[13.9%] and WNL 28[24.3%]. Radiologically, there were increased pulmonary vascularity in 104[90.4%] and cardiomegaly 62[53.9%]. Cardiac catheterization were performed in 101 cases and mean systolic pulmonary arterial pressure was 49.84*29.7mmHg and mean Qp/Qs was 2.95k1.8. Methods of operation were multiple ligation in 96, division in 11 and transpulmonary arterial repair using cardiopulmonary bypass in 8. Complication were recannalization in 2, temporary hoarseness due to left recurrent laryngeal nerve paralysis in 3 and respiratory distress in 1 and overall mortality rate was 1.7%[2 cases].