Necrotizing enterocolitis comprises ischemic and inflammatory bowel necrosis and occurs predominantly in premature neonates. It is an important cause of morbidity and mortality in neonatal intensive care units. Several factors are involved in the pathogenesis of this disease: genetic predisposition, intestinal immaturity, ischemic episodes, infections, enteral feeding and bacterial translocation. The diagnosis of necrotizing enterocolitis is based on clinical examination, laboratory studies and abdominal radiographs. A proportion of neonates with necrotizing enterocolitis can be cured conservatively. Surgical treatment is needed in case of intestinal perforation. The mortality rate of necrotizing enterocolitis is between 20% and 30%. The surviving neonates often suffer from long-term sequelae, including short bowel syndrome and neuro-developmental disability. Breastfeeding or feeding with mother’s expressed breast milk, together with early trophic feeding with slow increments, lowers the incidence of necrotizing enterocolitis in premature neonates. Prophylactic use of probiotics is useful, but its safety has not been established. This paper describes three cases of neonates with necrotizing enterocolitis in which the heterogeneity of risk factors and clinical signs is shown, along with a stepwise approach to the management of this disease.