A large body of literature shows that compared to children born at term, preterm- children are at increased risk for difficulties with inattention and hyperactivity. Less consistency exists, however, in the limited body of research exploring the contribution of early biological risk to behavioral disinhibition within the population of children born prematurely. Therefore, our goal was to examine perinatal variables that may influence activity level and hyperactivity among preterm preschoolers. Ninety-eight preterm (23.4 - 33.9 weeks gestation) preschoolers (3-4 years) participated in the study. Direct measures of inattention and hyperactivity as well as parental ratings were used to evaluate behavior. We used simultaneous linear regression analyses with gestational age, perinatal complications, and growth rate z-score (birth weight standardized by gestational age) as predictors of interest. Socioeconomic status, sex, multiple gestation, and age at testing were our covariates. Surprisingly, we found that within our preterm sample, total number of complications was inversely related to the CBCL Externalizing Problems scale score. Sex, but not perinatal medical status, was significantly related to performance on the NEPSY-II Statue subtest, with males displaying reduced ability for motor inhibition. Preschoolers with a greater number of complications obtained lower Externalizing Problems scale scores, suggesting a link between increased perinatal risk and reduced behavioral initiation. The reduced motor inhibition in boys, however, is consistent with the expected male outcome disadvantage documented in the prematurity literature