This paper analyzes the relationship between having one or more father figures and the likelihood that young people engage in delinquent criminal behavior. We pay particular attention to distinguishing the roles of residential and non-residential, biological fathers as well as stepfathers. Using data from the National Longitudinal Study of Adolescent Health, we find that adolescent boys engage in more delinquent behavior if there is no father figure in their lives. However, adolescent girls' behavior is largely independent of the presence (or absence) of their fathers. The strong effect of family structure is not explained by the lack of paternal involvement that generally comes with fathers' absence, even though adolescents, especially boys, who spend time doing things with their fathers usually have better outcomes. There is also a link between adult delinquent behavior and adolescent family structure that cannot be explained by fathers' involvement with their adolescent sons and is only partially explained by fathers' involvement with their adolescent daughters. Finally, the strong link between adolescent family structure and delinquent behavior is not accounted for by the income differentials associated with fathers' absence. Our results suggest that the presence of a father figure during adolescence is likely to have protective effects, particularly for males, in both adolescence and young adulthood.