Objective:To evaluate and compare the expression of the social smile of infants born preterm, with chronological age and corrected in order to provide more reasons for the effect of neurological maturation in this population. Method: This was an analytical, cross-sectional descriptive which saw the answer as to the behavior of the social smile in a cohort of premature infants in the third month of chronological age and corrected. To evaluate the expression of social smile, we used the Method of Assessment of Visual Infants. Results: It was found that, of 105 preterm infants evaluated, 75 (71.43%) responded positively to evidence of social smile on chronological age, while 99 (94.29%), corrected age (p 0.001 Â) .Conclusions: The expression of the social smile in infants born preterm, to be performed with the correction of gestational age allows these infants to express their real abilities.