Objective: This study aimed to determine the influence of participation in a designated acquired brain injury (ABI) transitional rehabilitation service (ABI TRS) on outcome, in the context of a historical comparison group (HIST). Design: A cohort study, with retrospective comparison. Participants: 187 persons with ABI. Measures: The Depression, Anxiety and Stress Scale (DASS-21), Mayo-Portland Adaptability Index (MPAI-4) and Sydney Psychosocial and Reintegration Scale (SPRS) were completed at discharge and 3 months after discharge. Participation in the ABI TRS involved interdisciplinary rehabilitation, 2–4 times per week, for 3 months after hospital discharge. Results: There was evidence that at 3 months, participants with ABI TRS showed stabilized psychological wellbeing, and improvements in MPAI-4 ability and participation scores; in addition to improvements in SPRS occupational activity and living skills scores. Conclusion: A designated ABI TRS may improve the transition from hospital to home, and could form an important part of the brain injury rehabilitation continuum, between the inpatient and community setting.