Although most fatal tumors are diagnosed well before a patient's death, occasionally forensic pathologists encounter cases in which the presence of a primary tumor of the central nervous system had not been suspected prior to death. A search for cases of sudden death due to intracranial tumors from a total of 1985 autopsies from the archives of the Department of Forensic Pathology, University of Ioannina, Greece, in the period 1998-2005, was undertaken. Two such cases in which a medico-legal autopsy had disclosed brain tumors were found. The first case was a 34-year-old man who had been found unconscious in bed, and died a few hours after hospitalization. His autopsy had revealed a 7-cm glioblastoma at the level of the third ventricle. The second case involved a 67-year-old man presenting with brain tumor, diagnosed 1.5 months previously. The patient had died after 16 hours of hospitalization. A 4-cm astrocytoma of the left temporal lobe had been found at autopsy. In both cases, the tumors may, directly or indirectly, have been the underlying cause of death. The importance of a thorough neuropathological examination in all cases of sudden death, in which no extracerebral cause had been found, is emphasized.