Neonates with severe respiratory distress syndrome who require high levels of assisted ventilation have a high mortality and morbidity rate. Morbidity is mainly composed of bronchopulmonary dysplasia which is a result of air leak syndrome(ALS), oxygen toxicity. Even with unsolved controversy, there is a possibility that high-frequency oscillatory ventilation would decrease the development or progression of ALS in infants with severe respiratory distress syndrome. ALS is defined as pulmonary interstitial emphysema or gross air leak such as pneumothorax. We experienced HFOV to be effective in the treatment of newborn infant with pneumothorax.