Accessory diaphragm associated with respiratory distress in a neonate

Supernumerary diaphragm is a rare congenital abnormality. This paper describes a neonate with respiratory distress caused by an overdistended left upper lobe and atelectasis of the left lower lobe entrapped below the accessory hemidiaphragm. Excision of the membrane dividing the hemithorax led to an uneventful recovery.