Bronchopulmonary dysplasia is caused by several factors. Avoidance of bronchopulmonary dysplasia is directed at its causes and should always attempt the rapid weaning of the patient from the respirator. Some of the preventive measures include a) avoiding an oxygen injury; b) prevention of barotrauma; 3) sufficient moisturization and warming of the respiratory gases; d) regular cleaning of the respiratory tract and bacterial controls of the tracheal secretion; e) administration of vitamin E; f) reconsideration (restricting the use) of parenteral nutrition. Assistance in the weaning from the respiratory means a) avoidance of an open ductus arteriosus; b) paced reduction of FiO2, respiratory pressure and frequency up to intermittent mandatory ventilation and final transition to spontaneous respiration with increased mean respiratory pressure; c) avoidance of cardiac insufficiency; d) administration of corticosteroids; e) theophyllin, and f) physical therapy. The number of patients with bronchopulmonary dysplasia has remained the same in the last six years. However, the mortality until 1979 round about 50% has been reduced to 1/3, in the years 1980/81.