Central nervous system (CNS) vascular malformations are well-known entities that may cause sudden death from rupture and intracranial hemorrhage. Despite this, relatively few papers deal with these lesions in the forensic literature. Here, we present four cases of sudden, non-traumatic death caused by ruptured CNS vascular malformations. In all four cases, the definitive source of bleeding was not identified grossly, being diagnosed only after relatively extensive histologic examination. When a source of intracranial hemorrhage is not readily identified at autopsy, it is common for forensic pathologists to rule the cause of death in such cases as "spontaneous intracerebral hemorrhage" or "spontaneous subarachnoid hemorrhage," depending on the location of the hemorrhage. Whether or not histologic evaluation is performed in such cases depends on pathologist preference or office policy, and may be influenced by limited available funding for such studies. Because vascular malformations are not always grossly visible at autopsy when accompanied by intracranial hemorrhage, we contend that it is important to thoroughly investigate the underlying cause of such hemorrhage through a meticulous gross examination as well as histologic examination. Such examination will lead to a more accurate assignment of the cause of death, which may have important implications for surviving family members, and will lead to a better understanding of the natural history of these intracranial lesions. A brief discussion of the histologic classification of CNS vascular malformations is provided.