Primary objective: To evaluate the benefits of the Brain Injury Family Intervention (BIFI) for families of persons with acquired brain injury and identify factors related to outcomes. Research design: Pre-test, post-test design with outcomes measured immediately after and 3 months following intervention. Methods and procedures: Family members and survivors participated in five 2-hour sessions over 10 weeks which included discussions of typical effects of brain injury, coping with loss and change, managing stress and intense emotions, effective problem-solving, setting reasonable goals and taking care of one's self. Guided by principles of family systems theory (FST) and cognitive behaviour therapy (CBT), the manualized treatment included educational, skill building and psychological support components. Main outcomes and results: Analysis of data derived from family members indicated a greater number of met needs and perceptions of fewer obstacles to receiving services post-treatment and at 3 months follow-up. Before and after treatment, unmarried caregivers reported more unmet needs. Family members of persons with longer acute care lengths of stay reported more unmet needs and greater perceived obstacles to services. Post-treatment differences in family members' psychological distress, satisfaction with life and functioning were not identified. Conclusions: The investigation provided evidence that family members benefit from interventions designed to meet their unique needs after brain injury. Uncertainties remain about the benefits of intervention to general family functioning and life satisfaction.