To quantify the rate of progressive failure of very-low-birth-weight (VLBW) infants over time in the neonatal intensive care unit to meet growth milestones. In a prospective longitudinal study, 114 VLBW preterm infants (1500 g) of both sexes, with normal and/or low weight for gestational age were included. At the start, weight, length, mid-upper arm (MUAC), thigh and cephalic circumferences were measured. Weight/age (W/A), length/age and weight/length (±2 z-score) indices were calculated. All measurements were taken at inclusion, at 7, 15 and 30 days of hospitalization. Chi-square test, analysis of variance and repeated-measures tests were estimated. Thirteen cases (14%) died and were excluded soon after the first determinations. In all, 9 (8.9%) died during the study, 12 (11.9%) were discharged before 30 days of life and 80 (79.2%) completed the study. At 7 days, the percentage of preterm infants with an index of W/A