Abstract In this paper we review biosocial research and theory in the area of antisocial behavior. In particular, we focus on interactions between biological and social variables in predicting antisocial outcome. While many psychological researchers make statements concerning the potential importance of biosocial interactions, very few researchers actually test for such interactions in their data. The few studies that have reported biosocial interactions suggest that biological variables can protect against antisocial behavior in socially vulnerable individuals, and that social variables can protect against antisocial behavior in biologically vulnerable individuals. Further research is necessary to determine whether the effects of biosocial interactions on antisocial outcome are dependent upon particular biological or social factors. Preliminary evidence suggests that policy interventions that ameliorate the effects of perinatal risk factors could protect against antisocial and violent outcome.