The objective of this investigation was to study weight changes at the postnatal period of 61 very-low-birth-weight newborns who survived out of 114 alive newborns from October 93 to October 94. They were grouped according to their birth-weight (750-999 g, 1000-1249 g, 1250-1499 g), gestational age ( or = 34 weeks) and adequacy of weight for gestational age (AGA, SGA). The weight variation was expressed in percentage according to the birth-weight and in g/kg/day. In all groups there was an initial loss of weight within the first five days of life. The groups which were smaller than 1250 g and younger than 30 weeks presented the greatest loss of weight and the longest period to recover it. The recovery of birth occurred similarly in all groups, with an average of 15 g/kg/day. The difference between the SGA and the AGA may be attributed to the groups' different gestational ages. Being aware of the way the newborns grow will permit early detection of deviations which may affect their quality of life.