This TIP, Substance Abuse Treatment: Group Therapy, presents an overview of the role and efficacy of group therapy in substance abuse treatment planning. The goal of this TIP is to offer the latest research and clinical findings and to distill them into practical guidelines for practitioners of group therapy modalities in the field of substance abuse treatment. The TIP describes effective types of group therapy and offers a theoretical basis for group therapy’s effectiveness in the treatment of substance use disorders. This work also will be a useful guide to supervisors and trainers of beginning counselors, as well as to experienced counselors. Finally, the TIP is meant to provide researchers and clinicians with a guide to sources of information and topics for further inquiry.