OBJECTIVE: Evaluate the functional performance of preschool children born with different degrees of prematurity and low birth weight who are follow in a care specialized service. METHODS: A cross-sectional study, which used the Pediatric Evaluation Disability Inventory- PEDI, an interview structured for caregivers that assesses children's functional abilities and independence level, in the areas of self-care, mobility and social function. The test was achieved with 98 participants divided into three groups according to the degree of prematurity and according to birth weight. It was used the chi-square test and the variance analys is to verify the association and the difference between groups according the degrees of prematurity (three) or birth weight (three) and the PEDI. In all analysis it was considered the significant level of α = 0,05. RESULTS: There was found a delay of 10,2%, 12,2% and 14,3% in the functional abilities in the areas of self-care, mobility and social function, respectively, and of 11,2%, 19,4% and 15,3% in the assistance level received from the caregivers (independence), in the same areas. It was not found statistically significant differences or associations between groups of different degrees of prematurity or birth weight and the PEDI performance. CONCLUSION: Premature and low birth weight children demonstrated high rates of delay in functional performance at preschool age that did not vary in magnitude among different degrees of prematurity and low birth weight, suggesting that exist others factors contributing to the development outcome at this age.