Objective To assess the safety, efficacy, temporary side effects and feasibility of oral ibuprofen suspension in the treatment of patent ductus arteriosus (PDA) with hemodynamic significance in premature infants. Method A randomized controlled trial including seventy-four premature infants with PDA was performed from February 2007 to May 2008. Infants were randomly assigned to two groups: testing group (36 patients) received three doses of oral ibuprofen suspension (10 mg/kg at 24-hour intervals) and control group (38 patients) did not receive such treatment. The cure rate of PDA, relative side effects of ibuprofen and complications during treatment were recorded.Results The closure rate of ductus arteriosus in the testing group was 52.8% (19/36), which was higher than that of control group (18.4%, 7/38) (χ2=9.575, P=0.002). The severe side effects did not occur in testing group, such as oliguria, renal impairment, prone of bleeding, gastrointestinal perforation and novel appearing or deteriorative of intraventricular hemorrhage (IVH). Compared with the infants in control group (26.3%, 10/38), the morbidity of abdominal distension or gastric retention in testing group (33.3%, 12/36) was higher, while there was no statistically significant difference (χ2=0.436, P=0.509). The hospital stay [(22.8±14.8) d vs (24.1±17.1) d], mechanical ventilation rate [5.6% (2/36) vs 2.6% (1/38)] and oxygen supplement time [(8.3±9.3) d vs (8.8±8.3) d] between the testing and control groups remained no significant difference (P>0.05). Conclusions Oral ibuprofen suspension could be effective in closing PDA of preterm infants; no significant complications and side-effects occurred during oral ibuprofen treatment. It is suggested that oral ibuprofen suspension treatment was safe, effective and well tolerated for preterm infants with PDA.