Phrenic nerve lesions as a result of birth trauma have been reported as a cause of acute respiratory distress infrequently. We report recent diagnostic and therapeutic experiences in four newborns with birth-traumatic phrenic nerve injury: one bilaterally, and three unilaterally, all right-sided. In each case, mechanical ventilation was required for at least 16 days. Ultrasound examination of the diaphragm and phrenic nerve conduction studies turned out to be the diagnostic methods of choice. Spontaneous recovery occurred in two children and two became asymptomatic after operative treatment. One improved after plication of diaphragm and one after autologous nerve transplantation.