A rare case of polyarteritis associated with a solid tumoris presented. A 66-year-old manwas referred to our hospital, because of gangrene in the bilateral fingers and toes, right pleural effusion, and an abnormal sensation in the throat. Adiagnosis of polyarteritis was madebased on pleuritis, digital gangrene and the arteriography findings. He also had a hypopharyngeal carcinoma. After being treated with intermittent intravenous cyclophosphamide, oral corticosteroid, alprostadil and aspirin, the pleural effusion rapidly disappeared, while the digital gangrene gradually improved. For the treatment of hypopharyngeal carcinoma, radiation therapy was initiated and resulted in complete disappearance. (Internal Medicine 41: 892-895, 2002)