The recent enthusiastic report of the use of continuous positive airway pressure (CPAP) prompts us to report our own experience with this method of therapy in infants with severe hyaline membrane disease. In 1968, four severely affected infants with hyaline membrane disease were treated with CPAP. The therapy was undertaken in infants whose clinical course was deteriorating under intermittent positive pressure breathing. The CPAP was applied by a negative pressure chamber that enclosed a child's chest, abdomen, and lower extremities.