The purpose of this study was to evaluate the effects of maternal protein and energy restriction during lactation on the body weight and tibiae dimensions of pups at aging. At parturition, Wistar rat dams were randomly assigned to the following groups: 1) control group (C) - free access to a standard laboratory diet containing 23% protein, 2) protein-energy restricted group (PR) - free access to an isoenergetic, protein-restricted diet containing 8% protein, and 3) energy-restricted group (ER) - fed restricted amounts of a standard laboratory diet. At weaning, all pups were separated of dams and received free access to a standard laboratory diet containing 23% protein until 180 days when the rats were anesthetized and sacrificed. The dimensions of excised pup tibia were measured directly using pre-established anatomical points. Morphometrical analysis of the tibia showed that most of the measurements in the ER and PR groups were significantly lower than in the control group, with the greatest reductions occurring in the PR group. These results show that protein and energy restriction during lactation have an important influence on pup tibia development