This article reviews the embryology, pathophysiology, clinical aspects and prophylactic treatment of respiratory distress syndrome (RDS). Prenatal prophylaxis with corticosteroids is indicated for gestational ages between 24 and 32 weeks, even if the effect of prophylaxis is uncertain before the 28th week. Prophylactic treatment is less important between the 32nd and 34th gestational week. Hypertension is not considered a contraindication, but premature rupture of the membranes is a relative contraindication. Corticosteroid treatment may be given, however, in combination with antibiotic prophylaxis.