The sequelae of severe closed head injury has received much attention in the literature, but the effects of mild closed head injury are less well established. The course of an 18-year-old female who sustained a mild closed head injury is presented. Substantial gains in intellectual function were observed over the year postinjury, with the most dramatic improvement coming in the first 6 months after the accident. Psychologic adjustment did not mirror the cognitive recovery. The implications of these findings are discussed.