Objective: To evaluate the effect of dexamethasone on the rate of respiratory distress syndrome in late preterm infants Materials and Methods: One hundred ninety-four singleton pregnant women at risk for late preterm delivery were randomly allocated into two groups. Ninety-seven patients received 6 mg dexamethasone (group 1) and 97 patients received 1.5 mL normal saline (group 2), intramuscularly every 12 hours for four doses or until delivery. The primary outcome was the rate of neonatal respiratory distress syndrome. The secondary outcomes were the need for continuous positive airway pressure (CPAP), the neonatal intensive care unit admission, the Apgar scores at 1 minute and 5 minutes, the rate of transient tachypnea of the newborn (TTN), intraventricular hemorrhage, neonatal hypoglycemia, neonatal sepsis, and adverse effects. Results: The rate of neonatal respiratory distress syndrome was lower in group 1, five cases (5.2%), compared with group 2, six cases (6.2%) (p=0.756, relative risk 0.83, 95% CI 0.26 to 2.64). The need for CPAP, NICU admission, rate of TTN, and intraventricular hemorrhage were not significantly different. Group1 had significantly higher Apgar scores at 1 minute and 5 minutes (p=0.021 and 0.043, respectively). No adverse effects were reported. Conclusion: Administration of dexamethasone in late preterm birth did not decrease the rate of neonatal respiratory distress and the need for CPAP and NICU admission but statistically significantly improved the Apgar scores at 1 minute and 5 minutes. More research in the future is needed to correct the limitation in the present study. Keywords: Late preterm, Dexamethasone, Respiratory distress syndrome, Apgar scores