In Binder et al. (1997) a metal-analytic review revealed a small effect size attributable to a history of mild head trauma (MHT). The results suggested a weak association between MHT and persistent neuropsychological deficits. In this paper, additional outcome data are summarized and the results are discussed. On a chronic basis, 7-8% of MHT patients remain symptomatic and 14% are disabled from work. Magnetic resonance studies of acutely injured persons may show lesions that are not detected in usual clinical practice. It is likely that the effects of these lesions dissipate with time, consistent with the neuropsychological data. The association between MHT and cognitive deficits, symptoms, and disability may not be casual; data suggest that MHT patients have more psychosocial problems prior to injury than do non-injured persons. The examiner of the MHT patient with chronic complaints must consider alternative medical and psychiatric explanations and perform a differential diagnosis. The possibility of a neurological basis for sustained neuropsychological problems cannot be completely dismissed. Presently, however, there is little evidence for neurological causation of most persisting complaints.