Objective: To evaluate the efficacy of a replicable group treatment program to improve social communication skills after traumatic brain injury (TBI). Design: Randomized treatment and defer-red treatment controlled trial, with follow-up at 3, 6, and 9 months post-treatment. Setting: Community. Participants: Volunteer sample of 52 people with TBI who were at least 1 year postinjury, who received rehabilitation, and who had identified social communication deficits. Intervention: Twelve weekly group sessions (1.5h each) to improve social communication. Main Outcome Measures: The Profile of Functional Impairment in Communication (PFIC), Social Communication Skills Questionnaire-Adapted (SCSQ-A), Goal Attainment Scale (GAS), Craig Handicap Assessment and Reporting Technique-Short Form social integration and occupation subscales, Community Integration Questionnaire social integration and productivity subscales, and Satisfaction With Life Scale (SWLS). Results: Independent samples t test analysis showed significant treatment effect compared with no treatment on 7 of 10 of the PFIC subscales (P range,.024 to <.001) and the SCSQ-A (P=.005) after the first 12 weeks of the study. After 12 weeks of treatment for all participants, repeated-measures analysis showed significant improvements from baseline on 9 of 10 PFlC subscales (P range,.01-.001), SCSQ-A (P <=.001), GAS (P <=.001), and SWLS (P=.011). At 6-month follow-up, scores were significantly better than baseline on 6 of 10 PFIC scales (P range,.01-.001), the SCSQ-A (P <=.001), GAS (P <=.001), and SWLS (P <=.001). Conclusions: TBI subjects who received social communication skills training had improved communication skills that were maintained on follow-up. Overall life satisfaction for participants was improved.