A previously healthy 9-year-old Japanese boy with a 4-day history of vomiting and headache died suddenly and unexpectedly. An external examination revealed no abnormalities other than foam around the mouth and nose. An internal examination revealed severe pulmonary edema and hemorrhagic hemangiopericytoma arising from the choroid plexus of the right lateral ventricle. The cause of death was thought to be neurogenic pulmonary edema caused by the rapid growth of a hemangiopericytoma, with intratumoral hemorrhage.