This review compares outcomes of adult postacute brain injury rehabilitation (PABIR) with natural recovery after brain injury. Potential outcome predictors and the effectiveness of behavioral, cognitive, pharmacologic, and vocational interventions are also appraised. The importance of standardized outcome assessment is discussed in the context of other research considerations. Although generally uncontrolled, the studies reviewed document benefits for many individuals with brain injury, including increased independence and a rate of return to independent work or training that exceeds 50% and may reach 60% to 80% for intensive comprehensive (holistic) day treatment programs. Available research is sufficiently encouraging to recommend more carefully controlled randomized studies. Future research should emphasize the development of standardized measures of patient characteristics and outcomes, and matching of patient characteristics with optimal rehabilitation approaches.