Background: Findings from prognostic studies of functional and psychosocial recovery after traumatic brain injury (TBI) reported to date have been limited by the restricted timeframe for prediction, generally within the first 5 years post-trauma. This investigation examined prediction of functional and psychosocial recovery in the medium-term (6 years post-trauma; Time 1) and long-term (23 years post-trauma; Time 2). Methods: The participants comprised a consecutive series of the first 100 patients with severe TBI receiving their primary rehabilitation at a regionally based unit. At the 23-year follow-up, 91% of the sample was traced: 17 had died, 5 declined participation, and 69 were interviewed, with 68 participating at both Time 1 and Time 2. Five outcome domains were examined: mobility, self-care, employability, relationships and living skills. Results: Very few of seven pre-injury variables were significantly correlated with any of the outcome variables. A series of logistic regression analyses successfully predicted levels of recovery in all domains using four predictor variables: pre-injury occupational status, duration of post-traumatic amnesia, and physical and neuropsychological disability at rehabilitation discharge. At Time 1, 60% or more of the variance was accounted for in four of the five domains, and at Time 2, more than 40% of the variance was accounted for in all domains. Sensitivity ranged from 62% (self-care) to 90% (mobility). With a single exception (employability at Time 2), specificity was also high, ranging from 80% (relationships) to 98% (mobility). Comparable accuracy rates were also found for positive and negative predictive power. Conclusions: These results demonstrate impressive predictive capacity of early post-trauma variables for the very long-term levels of recovery. They provide guidance for the tailoring of individual rehabilitation programs and the identification of people who may require special supports after rehabilitation discharge.