A 16-year-old boy was stricken with a progressive neurologic disorder characterized primarily by dementia progressing to severe neurologic debility in 12 months and death 28 months following the first symptoms. Pathologic examination showed a spongiform encephalopathy, consistent witha clinical diagnosis of Creutzfeldt-Jakob disease (CJD). The noteworthy features of the case are the age of onset, the somewhat prolonged course an the amount of white matter change. These are discussed within the frame of reference of CJD and the spongiform encephalopathies of infancy and childhood. Animal inoculation studies employing post-mortem embalmed brain as inoculum are currently in progress to determine the transmissibility of this patient's disease.