A case is reported in which there was a return of the electroencephalogram after a period of more than 36 hours of electrocerebral silence. Electroencephalographic technique and instrumentation were in accordance with the recommendations of Silverman, Saunders, Schwab and Masland. The possibilities of hypothermia or drug overdosage, known to reversibly depress the electroencephalogram, were excluded in the related case. The return of EEG activity was preceded by improvement in neurological status. It is concluded that criteria accepted for the determination of brain death in adults should not be valid for children.