An 18-year-old university student with Osler-Weber-Rendu disease collapsed in the bathroom. Attempted resuscitation was unsuccessful. Her past history included recurrent epistaxes, mucosal telangiectasias, intracranial arteriovenous malformations with previous hemorrhage, a single pulmonary arteriovenous malformation, recent onset of grand mal seizures, and depression. There was a positive paternal family history. At autopsy the pulmonary arteriovenous malformation was confirmed. In addition, within the brain there were widespread areas of gliosis with hemosiderin deposition and small vascular malformations. No other significant abnormalities were detected and toxicological screening revealed only moderately elevated levels of carbemazepine. Death was attributed to epilepsy associated with glial scarring from previous microhemorrhages. The detection of vascular malformations in the lung or brain at autopsy should prompt careful examination of all tissues for similar lesions. Given the possibility of Osler-Weber-Rendu disease in such cases, fibroblast cultures should be undertaken to enable molecular studies to proceed. The heritable nature of this disorder necessitates accuracy of diagnosis at autopsy; once the diagnosis is confirmed family screening should be recommended.