This paper reviews the functional outcome of patients sustaining mild and moderate head injury (HI). Discrepancies across studies in the definition of minor, mild, and moderate HI are discussed in terms of hindering the interpretation of recovery. The predictive value of acute severity indices, neuroimaging findings, and the results of other techniques are summarized. Measurement of outcome based solely on the Glasgow Outcome Scale (GOS) is critiqued, and it is recommended that a differentiated outcome scale involving emotional, behavioral, cognitive, and physical domains should be used.