Nine children with clinically suspected brain death were evaluated by radionuclide cerebral imaging and four-vessel dye contrast cerebral arteriography. The scans showing absence of cerebral blood flow were verified by arteriography in all children. There was complete agreement in all cases. It was concluded that failure to detect cerebral blood flow by radionuclide cerebral imaging in children is a valid demonstration of absence of cerebral circulation for purposes of determining brain death. The scan is significantly less expensive than dye-contrast arteriograms. The test is portable, and thus it eliminates the need for transportation of extraordinarily ill patients. The scanning technique is noninvasive and may be particularly helpful in the diagnosis of brain death in patients in whom intravenous infusions of barbiturate might otherwise obscure the clinical and EEG examination.