The main objectives of this study are to test racial differences in self-control and race-specific effects of self-control on drug-related problems. On the basis of prior research, it is hypothesized that both self-control and its effect on drug-related behavioral problems vary by race. Data collected from White, Black, and Hispanic inmates incarcerated in five local jails in the greater Philadelphia area were used to test these hypotheses. The results indicate significant racial differences in levels of self-control. However, the impact of self-control on drug problems did not differ significantly among the three racial groups. Overall, the findings support the argument of the general theory of crime that self-control maintains a constant and positive effect on deviant and criminal behavior across racial groups.