Background: This study is to suggest the optimal method as a treatment for the patent ductus arteriosus in the premature infants. Material and Method : Between April 1994 and April 1997, 45 premature infants with evidence of a hemodynamically significant patent ductus arteriosus associated with cardiopulmonary compromise underwent indomethacin therapy, surgical treatment, or both. Thirty-nine infants received indomethacin and twelve infants among them were surgically ligated because of indomethacin failure(5) or complications(7). Six infants, who weighed less than 1,500 gm at birth, were referred for primary surgical ligation because of contraindication to indomethacin therapy. Result: The failure rate of indomethacin therapy was 43%(17/39) and the complications(13/39, 33%) to the indomethacin were associated with a high morbidity and mortality. Among the infants who underwent ligation, there were no failures and complications related to the operation. This data suggests that in the premature neonate with a hemodynamically significant PDA, (1) indomethacin therapy is associated with a high failure rate and significant complications, (2) surgical duct closure is associated with minimal morbidity. Conclusion: Although the results of this study cannot suggest the optimal management for PDA in premature infants, primary surgical ligation may be considered. However, long-term studies will be needed to confirm this later.