Objective: To assess the effects of parenteral nutrition (PN) initiation time in very low birth weight neonates on: the birth weight recovery time, enteral nutrition (EN) initiation time, duration of hospitalization, and incidence of death. Methods: This retrospective case-control study was performed in the neonatal intensive care unit (NICU) of a tertiary center: Santo Amaro Hospital, Salvador, Brazil. All infants with birth weights ≤ 1500 g who were treated in the NICU during the study period (n= 114) were included. The sample was divided in two groups: early (≤ 48 h after birth) and late (> 48 h after birth) onset of PN. We also analyzed a subgroup of neonates with birth weights ≤ 750g, as well as a group for whom PN was initiated very early (≤ 24 h after birth). Results: A total of 114 neonates (n=48 / 39.8% in early PN group),were included in the study. Birth weight recovery time (9.9 ± 4.0 vs 12.8 ± 6.1, p = 0.007), lenght of hospitalization (43.2 ± 4.0 vs 71.8 ± 41.7, p = 0.007), and time of EN onset (2.2 ± 1.2 vs 7.9 ± 5.8, p <0.001) , were significantly lower in the early PN onset group than in the late onset group. Lenght of hospitalization was positively correlated with the timing of EN onset (r= 0,37, p = 0,001). No significant difference in adverse outcomes: death (18.6% vs 13.6%, p = 0.6), intracranial hemorrhage (ICH) (8.3% vs 12.1%, p = 0.9 ) and patent ductus arteriosus (PDA) (8.3% vs 31.8%, p = 0.1) was obbserved between groups. Conclusion: In this study, the early initiation of nutritional support in very low birth weight neonates can reduce the length of hospitalization thereby reducing costs, without increasing the incidence of adverse effects.