Standard pharmacologic closure of the patent ductus arteriosus currently involves the administration of 1 of 2 cyclooxygenase inhibitors: either indomethacin or ibuprofen. However, both of these drugs can be associated with potentially significant adverse effects. We present here the cases of 5 preterm infants (gestational age: 26-32 weeks; postnatal age: 3-35 days) with large, hemodynamically significant patent ductus arteriosus who had either failed or had contraindications to ibuprofen therapy. Each of these infants was treated with off-label oral paracetamol (15 mg/kg per dose every 6 hours). Ductal closure was achieved within 48 hours in all the treated infants. No toxicity was observed.