Between 1974 and 1991, we treated 10 aortic arch branch aneurysms in eight men and two women, who ranged in age from 17 to 81 years old (mean age, 55 years). Five patients had subclavian artery aneurysms, four had carotid artery aneurysms, and one had an inominate artery aneurysm. The chief complaint was a mass on the neck and supraclavicular fossa in five patients, rupture and an abnormal shadow on chest X-rays in two patients each, and acute artery occlusion in the upper limb in one patient. The operative method was usually excision of the aneurysm and reconstruction. The causes were arteriosclerosis in five patients, the thoracic outlet syndrome in two patients, and inflammatory, traumatic and iatrogenic in one patient each. Intraoperative hemorrhage occurred in one patient and graft occlusion in another one. The other patients have had a good course. This disease is rare, but because of complicated rupture and acute artery occlusion, it is desirable to perform surgery as soon as possible after the first diagnosis.