The authors studied 538 patients who had sustained minor head trauma, which was defined as a history of unconsciousness of 20 minutes or less, a Glasgow Coma Scale score of 13 to 15, and hospitalization not exceeding 48 hours. Of these patients, 424 were evaluated 3 months after injury. The follow-up evaluation included a history of events since the accident, assessment of subjective complaints and objective measures such as employment status, a neurological examination, a psychosocial assessment designed for estimating life stress, and a neuropsychological test battery to measure higher cortical function. Of these 424 patients, 79% complained of persistent headaches, and 59% described problems with memory. Of the patients who had been gainfully employed before the accident, 34% were unemployed 3 months later. Comparisons were then made between the employed and the unemployed groups. Three explanations for the high rate of unemployment were examined. (a) Evidence of organic brain damage:​ Although the neurological examination was completely normal in nearly all patients, neuropsychological testing demonstrated some problems with attention, concentration, memory, or judgment in most of the 69 patients evaluated. (b) Psychological responses to the injury:​ Emotional stress caused by persistent symptoms seems to be a significant factor in the long term disability of these patients, (c) Litigation and compensation:​ These factors have a minimal role in determining outcome after minor head injury. In conclusion, these studies are the high rates of morbidity and unemployment in patients 3 months after a seemingly insignificant head injury and the evidence that many of these patients may have, in fact, suffered organic brain damage.