Background: There are limited data on the interactions between concomitant spinal cord injury (SCI) and traumatic brain injury (TBI) in terms of medical, psychological, functional, and community outcomes. Objective: To investigate the hypothesis that in addition to SCI-associated sensory-motor impairments, people with dual diagnosis would experience additional TBI-associated cognitive impairments that would have a negative impact on community reintegration. Methods: Cross-sectional, case-matched study comparing a consecutive sample of participants with dual diagnosis (n = 30) to an SCI group (n = 30) and TBI group (n = 30). Participants who were on average 3.6 years postrehabilitation discharge were interviewed using a battery of standardized outcome measures. Results: Length of rehabilitation stay was significantly longer in SCI and dual diagnosis participants. Fatigue, pain, sexual dysfunction, depression, and sleep disturbances were frequently reported by all groups. Similar levels of anxiety and depression were reported by participants in all groups, however TBI participants reported higher stress levels. All groups achieved mean FIM scores > 100. The dual diagnosis and SCI groups received more daily care and support than TBI participants. Similar levels of community reintegration were achieved by all groups with a high level of productive engagement in work, study, or volunteer activities. Conclusions: The findings of this study do not support the hypotheses. Postrehabilitation functioning was better than anticipated in adults with dual diagnosis. The contribution of rehabilitation factors, such as longer admission time to develop compensatory techniques and strategies for adaptation in the community, may have contributed to these positive findings.