In our study, univariate analysis revealed significant difference of sex, mean gestational age, cesarean section, mean birth weight, surfactant replacement therapy and mean PIP and PEEP between case and control groups. In regression analysis only surfactant replacement therapy significantly reduced the risk of pneumothorax in ventilated newborns. Only 32.4% of newborns with pnemothorax received surfactant compared to 60.4% of neonates under ventilation without pneumothorax. This difference between the two types of analysis may be due to internal relationship of other variables with each other or because of low sample volume. More studies is suggested with matching of variables in a larger sample volume.