Although adherence to aftercare therapy in substance abuse treatment is associated with improved treatment outcome, relatively little research has explored methods of improving aftercare adherence. To improve on established methods of promoting aftercare adherence, 43 graduates of the 28-day intensive substance abuse treatment program at the Salem Veteran's Affairs Medical Center who received standard aftercare orientation are compared to 38 graduates who received the standard intervention plus social reinforcement of aftercare group therapy attendance. Clients who received social reinforcement attended more aftercare group sessions than did clients who received the standard treatment during the 8-week intervention (68.8% vs. 49.4% of sessions attended), and during the 4-week follow-up period (41.5% vs. 31.4% of sessions). These findings are noteworthy since the standard treatment had been shown to be effective in increasing aftercare adherence in prior studies (Lash, 1998; Lash & Blosser, 1999). Areas for future research are discussed.