Introduction. Necrotizing enterocolitis is a multifactorial catastrophe to newborns; it is caused by splacnich bed vasoconstriction that produce intestinal necrosis. The role of onset time, type and, speed enhancements of enteral feeding related with necrotizing enterocolitis genesis are discussed today.Objective. To compare the incidence of necrotizing enterocolitis and mortality among infants in whom enteral feeding was started 48 hours after birth compared to others that began on the fifth day of life.Materials and methods. Controlled clinical trial was conducted among 239 newborns between 750 to 1.500 g and 27-32 weeks of gestational age, randomly assigned 135 to early feeding and 104 to delayed feeding; breast milk or formula milk for infants were used. Feeding began with one mL every six hours, to progress at three hours intervals daily and increased to 20 mL/kg-d to reach 150 mL/kg-d while any patient remained stable and showed no oral intolerance manifestations.Results. There were 14 necrotizing enterocolitis cases in early feeding group (10.4%) and nine (8.7%) in late feeding one (RR= 1.22, 95% CI 0.49-3.20, p= 0.652). Five children died in early feeding group (3.7%, 95% CI 1.4-8.9) and eight in late feeding one (7.7%, 95% CI 3.6-15.0, RR= 0.46, 95% CI 0.12-1,60, p= 0.182).Conclusion. The start in early enteral feeding in preterm newborns does not increase the risk of necrotizing enterocolitis or mortality among them, and does represent great advantages for these patients.