PURPOSE: Antenatal steroid(ANS) therapy in premature infants is an effective therapeutic strategy in reducing the incidence of respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, and patent ductus arteriosus. For premature infants to gain improved survival, adequate weight loss during early postnatal days and maintenance of electrolyte balance is important, however, it is uncertain that ANS affect them. We hypothesized that ANS augment fluid and electrolyte balance and dinical outcome of very low birth weight(VLBW) who had received restricted fluid regimen. METHODS: Mechanically ventilated VLBW infants who survived over 30 days were selected. We reviewed medical records to compare weight loss, urine output, electrolyte concentration, blood pressure during five days of life and clinical outcome between premature infants who received ANS(n=15) and who were not(n=58). RESULTS: Gestational age, birth weight were similar between two groups. Volume of administered fluid, urine output, and initial weight loss during first five days of life were similar, however, weight loss on postnatal day five were lower in study group than control group(p=.039). Blood pressure, serum sodium concentration, serum potassium concentration, and urine specific gravity were similar between two groups. Incidence of respiratory distress syndrome was lower in study group(20%) than control group(48%)(p=.041), however, incidence of sepsis were greater in study group(33%) than control group(7%)(p=.029). CONDUSION: ANS did not affect fluid and electrolyte balance of very low birth weight(VLBW) infants who had received restricted fluid regimen. ANS decreased the incidence of respiratory distress syndrome in this population, however, increased the incidence of sepsis.