Background: In neonatal respiratory distress syndrome patients, various types of pulmonary air leak contributes to elevate morbity and mortality. Although early surgical interventions can provide better results in several cases, whole clinical outcomes are poor. This study was designed to investigate the clinical aspects of pulmonary air leak in the neonatal respiratory distress syndrome patients and major contributing factors to mortality. Material and Method : We retrospectively evaluated 48 cases of pulmonary air leak in the neonatal respiratory distress syndrome patients from September 1994 to May 1997. Result: There were 15 cases of primary and 33 cases of secondary pulmonary air leakages. The prominent manifestations were pure interstitial emphysema in 19 cases(39.9%) and combined pneumothorax in 19 cases(39.9%). In clinical aspects, normal birth weight was dominant(83.4%), the onset occurred within 24 hours was in 28 cases(58.8%). The pulmonary diseases were meconium aspiration syndrome(25.2%) and hyaline membrane disease(33.2%). The overall hospital mortality was 25.2%, and the majority were hyaline membrane diseases. Conclusion: Although the overral mortality rate of these diseases were high, more detailed studies about immediate treatement, perinatal prevention, intensive care to geriatric problems were needed individually to improve outcomes.