Background: We aimed to evaluate the efficacy and safety of early surgical ligation (within 15 days of age) over late surgical ligation (after 15 days of age) by a comparative analysis of very low birth weight (VLBW) infants undergoing surgical correction for symptomatic patent ductus arteriosus (PDA) over the course of 6 years in our hospital. Methods: We retrospectively reviewed all the medical records in the neonatal intensive care unit at Hanyang University Seoul Hospital, from March 2007 to May 2013, to identify VLBW infants (<1,500 g) who underwent surgical PDA ligation. Results: The gestational age (GA) in the late ligation (LL) group was significantly younger than in the early ligation (EL) group (p=0.010). The other baseline characteristics and preoperative conditions did not differ significantly between the two groups. The intubation period before surgery (p<0.001) and the age at surgery (p<0.001) were significantly different. The postoperative clinical outcomes of the study patients, including major morbidity and mortality, are summarized. There were no significant differences in bronchopulmonary dysplasia, sepsis, or mortality between the EL and the LL groups. However, the LL group was significantly associated with an increased risk of necrotizing enterocolitis (p=0.037) and with a prolonged duration of the total parenteral nutrition (p=0.046) after adjusting for GA. Conclusion: Early surgical ligation for the treatment of PDA that failed to close after medical treatment or in cases contraindicated for medical treatment might be desirable to reduce the incidence of necrotizing enterocolitis and to alleviate feeding intolerance in preterm infants.