Objective: To evaluate the frequency of necrotizing enterocolitis, intrinsic risk factors associated with newborns and mothers, and effects of these factors on the development of NEC and related mortality in our newborn intensive care unit. Material and Methods: Three hundred and thirty two newborns admitted to our intensive care unit with the diagnosis of NEC between January 2002 and August 2010 were evaluated retrospectively. Results: The frequency of NEC in our NICU was found as 3.8 percent. Only 5 of the subjects were term, and remaining 327 were preterm infants.The mean birth weight and gestational age of the preterm infants were 1265±338 g and 30.9±2.7 weeks respectively. The most important risk factors for NEC were perinatal asphyxia, severe RDS, ventilatory treatment, umbilical catheterization and use of aminophylline. In cases with NEC, proven sepsis rate was 9% and the gram negative bacteria were found as the most common organisms in these cases. Frequency of trombocytopenia was 32.5% which was significantly higher in cases with severe NEC. In preterm infants with birth weights of <1000 grams, onset of symptoms was delayed (14-28 days), the duration of hospital stay was longer and rates of surgical treatment and mortality were higher which were all statistically significant. A total of. 24 infants were treated surgically. Surgical, and overall mortality rates were 24% and 11%, respectively. Conclusion: Necrotizing enterocolitis is an important disease of high risk prematures below 32 weeks of ages, and this morbidity will continue to be a problem of intensive care units as the survival rates of very premature infants increase.