Management of patent ductus arteriosus (PDA) in full-term neonates remains controversial. We evaluated the effects of oral ibuprofen on PDA closure in 51 full-term neonates. All neonates were >3-days-old and had a gestational age > or = 37 weeks. Patients with ductal-dependent congenital heart disease or severe pulmonary artery hypertension (gradient >40 mmHg) were excluded. Patients were randomly assigned to the treatment group (n = 30) or the control group (n = 21). The treated group received ibuprofen suspension (initially 10 mg/kg, then two 5-mg/kg doses 24 h apart), and control neonates received a placebo. Physicians who treated the patients were blinded to group assignment. There was a statistically significant difference in the closure rate of PDA between the treated (73.3%) and control groups (42.9%, P = 0.029). Among neonates with PDA closure, there was a significant difference in the day of closure between the two groups (25.49 and 17.65% on the days 4 and 14 after diagnosis of PDA in treated neonates versus 1.96 and 15.69% in controls, respectively). This study showed the efficacy of oral ibuprofen in achieving earlier closure of PDA in full-term neonates.