The records of all patients with aneurysm of the subclavian-axillary artery who were seen between January, 1960, and January, 1980, were reviewed. There were 31 patients (21 male and 10 female) with a mean age of 47 years. The aneurysm (mean size, 3.0 cm) was located on the right in 20 patients and on the left in 10; one patient had bilateral aneurysms. Mural thrombus was present in 25 patients. Eight patients were asymptomatic and 23 presented with upper extremity pain. Thromboembolism occurred in five patients, one presenting with impending loss of tissue. Two patients had the aneurysm rupture and one of them died. A pulsating mass was palpable in 20 patients, including the eight who were asymptomatic. Vocal cord paralysis occurred in two patients. The cause of the aneurysm was atherosclerosis in 12 patients, trauma in 10, poststenotic dilation secondary in thoracic outlet obstruction in 6, mycotic aneurysm in 2, and Ehlers-Danlos syndrome in one patient. Seven patients had nine aneurysms in other areas. Surgical treatment consisted of thoracic outlet decompression in 4 patients, graft interposition in 11, tangential aneurysmorrhaphy in 8, ligation in 4, and exploratory surgery only in one. One forearm amputation was subsequently performed. Three patients did not undergo surgery. Average length of follow-up was 9.2 years. Except for the patient who underwent amputation, all treated patients had adequate circulation in the extremities. No aneurysm recurred and no complication of the repair developed. We conclude that aneurysms of the subclavian-axillary artery, although rare, are both life- and limb-threatening. Resection and arterial reconstruction are recommended.