This is prospective descriptive study by collecting data of neonates diagnosed with pneumothorax in neonatal intensive care unit (NICU) in Cairo University Pediatric Hospital during the period from July 2012 to December 2012, which included 35 cases (13.61%), out of the total number of 257 patients who were admitted at this period. On studying the demographic and clinical characteristics of cases and risk factors implicated in incidence of pneumothorax, it’s reported that 65.7% of cases were males, 82.9% born by caesarean section, 82.8% with gestational age < 37 weeks, 71.4% with birth weight < 2.5 kilogram. Pneumothorax in 60% of cases was late onset at postnatal age older than 3 days, and respiratory distress syndrome was the most prevelant underlying lung disease. 94.2% of patients were under positive pressure ventilation. Pneumothorax was in 71.4% of cases at right side, and in 77.1% of cases, pneumothorax was moderate or severe causing respiratory or cardiac compromise.During admission, 23 patients died with mortality rate 65.7% of all patients presenting with pneumothorax, and hypoxia with oxygen saturation <90% was in deceased cases and highly significantly different (p<0.05) from survived cases.