Objective: The present study sought to compare the motor development of the preterm infants of two Brazilian regional samples, using a reliable scale evaluation to determine the influence that the environment can have on infants exposed to perinatal conditions and similar risk factors. Materials and Methods: Two cross-sectional samples of preterm low-birthweight infants were used: a study group (SG = 70) and a control group (CG = 43). The assessment tool used was the Alberta Infant Motor Scale (AIMS). Results: There were no statistically significant differences in total score on the AIMS, although some differences were noted in the gestational age variable (at 2, 3 and 4 months of age) and the birth weight variable (weight slightly above that of the CG) among infants. There was also a difference in the classification of motor development at 2 and 3 months of age corrected in accordance with the standard scale, on which the SG was ranked as behindhand in relation to the CG. Conclusion: The results suggest that preterm infants from different regions show the same rate of progress in their motor development, even when subject to different environmental influences. It is, further, suggested that this study should be extended so as to permit a more detailed control of the environment (including the maternal practices) in which the infant is being brought up.