Background Necrotizing enterocolitis is one of the commonest neonatal gastrointestinal diseases. Which stays similar in terms of epidemiology despite many preventive strategies have been done longer. Despite the etiologies are multifactorial, maternal and neonatal factors may have direct or indirect association in terms of prevalence and age at onset.it mainly affects preterm neonates which accounts around 90% of the cases. Around 2/3 of cases develop within 2 weeks of age and 1/3 of cases develop later .the age of occurrence is inversely proportional with the gestational age. Gestational age, formula feeding, prolonged parenteral nutrition, sepsis and perinatal asphyxia have strong association with Necrotizing enterocolitis. Objectives The main objective of the study was to determine the proportion of Necrotizing enterocolitis for one year with age of onset of the disease and determinant factors for the development of Necrotizing enterocolitis, Felege hiwot comprehensive specialized hospital; North West Ethiopia, Ethiopia; 2018 G.C. Methods, Retrospective cross-sectional study was conducted from Agust1-november 15/2019. All patient data from patient recorded log books of NICU January 1st, 2018 to December 30, 2018 was included in the study. Data was collected by well-prepared abstraction sheet by principal investigator and trained health worker. The data was cleaned and checked for completeness, entered by Data entry clerk and SPSS version 20 software package was used for analysis. The detailed and relevant prenatal, perinatal and postnatal factors were included. The detailed clinical manifestation and diagnostic investigations were taken and interpreted. The proposal was approved by the ethical committee of Bahir Dar University and permission was obtained from Amhara public health institute and the responsible bodies of Felege Hiwot comprehensive specialized Referral Hospital. Result The proportion of necrotizing enterocolitis in this study was 16.6% and almost 84% of cases develop within the first one week of life. Around 70% of cases were stage two and above according to bell’s staging.72.3% of cases were below 32 weeks of gestational age. And two third of all were less than 1500 gram. Gestational age and birth weight were inversely related with necrotizing enterocolitis. One minute Apgar score less than 3 (AOR=2.6, 95%CI=0.5, 13), blood transfusion (AOR=1.85, 95%CI=0.92, 3.7), out born delivery and slow feeding advancement were associated factors with necrotizing enterocolitis. Conclusion The proportion of necrotizing enterocolitis is high in this study. Majority of cases were early onset. Gestational age, birth weight, and rate of feeding advancement were associated with necrotizing enterocolitis. But to validate this study larger sample and multicentered prospective study should be done which may be important to consider preventive strategies. Key words Necrotizing enterocolitis, preterm, trophic feeding