We treated 2 very low birth weight (VLBW) infants with respiratory distress syndrome suffering from refractory hypoxic respiratory failure complicated with severe pulmonary hypertension with inhaled iloprost. The first infant was an 800 gram male and the second case was a 920 gram female. Echocardiography revealed a right to left shunt through patent duct in the first case; suprasystemic pulmonary arterial pressure was estimated by using tricuspid regurgitation of moderate severity in the second case. Inhaled iloprost was started in those infants when conventional therapies including the administration of exogenous surfactant and high-frequency oscillatory ventilation failed. After the commencement of therapy, the clinical condition of the infants improved dramatically. Pulmonary arterial pressure returned to normal levels within five days. We suggest that inhaled iloprost may be helpful by improving oxygenation and reducing the need for aggressive mechanical ventilation in some cases of severe hypoxaemic respiratory failure in VLBW infants.