Few studies have addressed comorbid antisocial personality disorder (ASPD) and marijuana dependence in young adults, and results from previous studies are inconsistent. Objectives: This study evaluated differences in pretreatment characteristics and treatment outcomes between marijuana-dependent young adults with and without ASPD. Methods: Data for this study were derived from a randomized trial, in which marijuana-dependent young adults (n 136) between 18 and 25 years of age were randomized to four behavioral conditions: (1) MET/CBT with CM, (2) MET/CBT without CM, (3) DC with CM, and (4) DC without CM. Results: Forty-four percent of the participants met DSM-IV-TR criteria for ASPD. ASPD clients had significantly more lifetime alcohol dependence disorders, marijuana use in the 28 days pretreatment, arrests, and assault and weapon charges compared to those without ASPD. ASPD clients did not differ in retention or substance use outcomes at 8 weeks posttreatment or the 6-month follow-up. In general, both groups had more attendance in the voucher condition, but there were no significant ASPD by treatment interactions. Conclusions: These data suggest that marijuana-dependent young adults with comorbid ASPD do not necessarily have poorer retention or substance use outcomes compared with marijuana-dependent young adults who do not have ASPD when treated in a well-defined behavioral therapy protocol. Scientific significance: Previous research has shown increased risks for clients with comorbid ASPD and marijuana dependence; however, our findings suggest that specialized programs for clients with ASPD may not be necessary if they are provided with empirically supported, structured treatments. © 2012 Informa Healthcare USA, Inc.