Infants with primary pulmonary hypoplasia with respiratory distress immediately after birth, but usually elude early diagnosis. They have no other abnormalities, but frequently develop signs and symptoms of the PFC syndrome. Roentgenographically, they show small, clear lungs and are prone to develop complicating pneumothoraces. The clinical, roentgenographic, and pathologic features of eight infants with primary pulmonary hypoplasia are presented.