Delayed nonhemorrhagic encephalopathy following mild head trauma is a rare condition with an unknown etiology. The few cases reported in the literature are in young adults, all of them in the era before computerized tomography (CT) became available, and all had a devastating clinical course with multifocal ischemia or necrotic lesions found at autopsy. A case is presented of a young man with this syndrome who survived the acute encephalopathic phase with severe residual neurological deficits. Repeat CT scans during and following the acute phase as well as magnetic resonance imaging showed diffuse multifocal lesions compatible with ischemic changes and demyelination in the "watershed" areas of the brain.