Ten cases of transient respiratory distress of the newborn (TRDN) are presented and the roentgenographic and clinical findings discussed. The literature is reviewed and an etiology considered. It is postulated that the condition is caused by a transient impairment of normal clearing of fluid from the newborn lung, and it is felt that it represents a temporary disturbance of normal neonatal pulmonary physiology. It is also believed that transient respiratory distress of the newborn is more common than currently realized and that its recognition will account for a large number of "normal" infants with unexplained, fleeting neonatal respiratory distress.