© 2020 Sociedad Argentina de Pediatria. All rights reserved.Aim. To investigate NEC frequency in premature infants and assess risk factors associated with disease-onset and progression to intestinal perforation. Methods. Retrospective cohort in preterm neonates hospitalized between 2015 and 2018. Perinatal characteristics, clinical features, nutritional data and laboratory outcome were analyzed using SPSS-23 statistical package. Logistic regression was performed to analyze associated risk factors. Results. In 1428 neonates, the rate of developing NEC was 18.28 %. Conception with assisted reproductive technology, cesearean section and postnatal-steroids were associated with NEC (OR: 4.056, 95 % CI: 2.810-5.854, OR: 1.961, 95 % CI: 1.321-2.910, OR: 6.422; 95 % CI: 4.327-9.530). Timing of first enteral feeding was associated to developing NEC, but not to intestinal perforation (p < 0.001, p = 0.604). Forty-seven of 261 NEC patients (18 %) have developed intestinal perforation. Antenatal steroids showed to reduce severe consequences (p = 0.001). Timing of first enteral feeding and hemodynamically significant PDA were predisposing factors for NEC and low 5-minutes Apgar score for intestinal perforation. (OR: 6.515; 95 % CI: 5.011-8.470; OR: 4.715; 95 % CI: 2.717-8.183; OR: 2.748; 95 % CI: 1.100-6.866). Mortality was 9 %. Developing NEC increased risk of mortality by 2.192 times (95 % CI: 1.469- 3.271); in intestinal perforation, mortality risk increased to 11.527 (95 % CI: 6.293-21.115). Conclusion. NEC frequency was 18.28 %. Intestinal perforation occurred in 18 % of NEC patients. PDA and delay in first enteral nutrition were predisposing factors for acquiring NEC and low 5-minutes Apgar scores for intestinal perforation.