Minor traumatic brain injury is the most common type of traumatic encephalopathy, with approximately 290,000 to 325,000 new cases occurring each year. Recent research has suggested that both anatomic factors (acceleration-deceleration injury, contusions) and neurotransmitter factors (cholinergic systems) may contribute to the pathologic sequelae. Symptoms may be broadly categorized as physical, behavioral/affective, cognitive and integrative. Patients with mild brain injury may demonstrate significant attention and information-processing impairments in the absence of apparent neurologic problems. Most symptoms abate within the first few months, but a sizable subgroup of patients remain symptomatic up to one year or more. Evidence suggests that patients whose symptoms persist are not simply "neurotic." Rehabilitation efforts should focus on proper evaluation, reassurance, education, support and monitoring of progress.