We examined 26 preterm infants with respiratory distress syndrome in a randomized controlled prospective study to determine whether early postnatal dexamethasone therapy (< 2 h; 0.5 mg/kg per day) over 5 days in addition to substitution of surfactant (100 mg/kg) facilitates extubation and the course of RDS. Control (n = 12) and treated (n = 14) groups were comparable in birthweight (mean +/- SD: 1219 +/- 292 versus 1446 +/- 442 g), gestational age (29.3 +/- 2.2 versus 30.6 +/- 2.7 weeks), prenatal characteristics and initial respiratory and blood gas parameters. In both groups one infant died. Infants in the dexamethasone group responded better to surfactant (12/14 versus 3/12; p < 0.01), were extubated earlier (6.6 versus 14.2 days; p < 0.02) and required less time on supplemental oxygen (4.2 versus 12.5 days; p < 0.02). Pulmonary complications tended to be lower in the dexamethasone group (1/14 versus 4/12), as was the frequency of retinopathy (2/14 versus 6/12; p < 0.05). We conclude that early postnatal dexamethasone therapy improves response to surfactant therapy resulting in better weaning and earlier extubation in premature infants.