PurposeThe purpose of this paper is to examine whether early language deficits increase the risk of severe antisocial behavior among male children, and whether this association varies as a function of negative temperament during infancy.Design/methodology/approachData are derived from the Early Childhood Longitudinal Study, Birth Cohort. Both survey methods and direct observations were employed to obtain the data. Logistic regression was used to examine the research questions at hand.FindingsMale children with oral vocabulary and grammatical/syntactic deficits during the toddler years exhibited more frequent antisocial behavior across home and school settings during kindergarten, relative to boys without language deficits. However, this relationship was limited to males who manifested negative temperament/affect during their infancy, as reported on by both parents and independent raters.Originality/valuePrior research on language, temperament, and antisocial behavior has generally overlooked the potential for these early-life risk factors for subsequent offending to interact with each other. The findings of the present study suggest that early intervention and prevention efforts should account for ways in which individual temperamental differences can structure behavioral responses to cognitive challenges.