A 73-year-old woman with a three-year history of allergic rhinitis and bronchial asthma was found to have Churg-Strauss syndrome combined with fever, eosinophilia, mononeuritis multiplex, and acute coronary syndrome. After the treatment with a methylprednisolone pulse therapy and a high dose of corticosteroids were initiated, eosinophilia normalized together with decline of fever, but acute superior mesenteric artery occlusion occurred, which improved with conservative therapy. Severe stenosis of bilateral carotid arteries was found, so immunosuppressive drugs were added. In general, Churg-Strauss syndrome is a disease with vasculitis affecting small arteries, arterioles, venules, or capillaries, and cases with arteritis in large and medium-sized arteries, such as this case are rare. This suggested that in cases of Churg-Strauss syndrome of the elderly patients, physicians must be careful about involvement of larger vessels.