A 53-year-old woman with no classic risk factors for aneurysm disease presented with the sudden onset of chest pain and dyspnea. A large descending thoracic aortic aneurysm with focal type B dissection was identified and excluded by emergency thoracic endografting. Further postoperative evaluation revealed a history of epistaxis, perioral telangiectasias, hepatic hypervascularity, and a mutation in the gene expressing activin receptor-like kinase 1 (ALK1), leading to a diagnosis of hereditary hemorrhagic telangiectasia. Aortic aneurysms associated with hereditary hemorrhagic telangiectasia are extremely rare, and to our knowledge, this is the first report of thoracic endografting in this patient population.