The authors present two cases of clinical brain death that failed to meet the criteria for whole brain death using Tc-99m HMPAO. Conventional anterior cerebral flow studies demonstrated no intracerebral perfusion. Anterior static images also failed to show cerebral activity. However, the lateral images clearly demonstrate cerebellar activity. These cases demonstrate the importance of Tc-99m HMPAO as the agent of choice in evaluating brain death and the necessity of lateral views to meet the criteria for whole brain death. Cerebellar perfusion challenges the present criteria for whole brain death. New criteria must re-evaluate the present technology.