Drug and alcohol abusers frequently have legal difficulties, and the legal system often provides negative reinforcement for substance abuse treatment. In contrast, contingency management (CM) treatments utilize positive reinforcement procedures to improve patient outcomes. This study evaluated whether substance-abusing patients with legal problems at treatment entry had differential outcomes, in general and in response to CM, compared with those without legal problems. Data from three randomized CM trials (n = 393) were used in an evaluation of main and interactive effects of legal status and treatment condition, with respect to retention and abstinence. Compared with patients without legal difficulties, those with legal problems remained in treatment for shorter durations and achieved shorter periods of abstinence. CM was positively and significantly associated with longer durations of abstinence, regardless of legal status. Results suggest that substance abusers with legal problems have generally poor outcomes, but that CM is effective regardless of the patient's legal status.