Pediatric neurologists agree that the determination of brain death in children, and especially retarded children, is difficult and that the criteria used in adult brain death may not be sufficient in pediatric cases. An unusual case of sustained electrocerebral silence on electroencephalogram (EEG) in a three-year-old retarded comatosed child with preserved intracerebral perfusion documented by a series of cerebral radionuclide angiograms (CRAG) is presented. The EEG showing electrocerebral silence represents loss of cerebrum (cortex) function (Barlow 1976). This absence of cortical function is demonstrated even though intracranial circulation is shown to be intact. We believe that the correlative studies presented accurately document a discordance between apparent loss of cortical function in a child as indicated by electrocerebral silence in the face of preserved cerebral blood flow. It is suggested that when evaluating brain death in retarded children with known cerebral atrophy, special emphasis should be placed on the CRAG and that the EEG should be read with caution.