Anger and related emotions have been identified as triggers in substance use. Forgiveness therapy (FT) targets anger, anxiety, and depression as foci of treatment. Fourteen patients with substance dependence from a local residential treatment facility were randomly assigned to and completed either 12 approximately twice-weekly sessions of individual FT or 12 approximately twice-weekly sessions of an alternative individual treatment based on routine drug and alcohol therapy topics. Participants who completed FT had significantly more improvement in total and trait anger, depression, total and trait anxiety, self-esteem, forgiveness, and vulnerability to drug use than did the alternative treatment group. Most benefits of FT remained significant at 4-month follow-up. These results support FT as an efficacious newly developed model for residential drug rehabilitation.