Aneurysms of the extracranial carotid artery are an uncommon but potentially serious problem, usually due to rupture or thromboembolic events. Thirty-seven aneurysms of the extracranial carotid artery were seen in thirty-four patients from 1956 to 1977. The ages ranged from twenty-nine to ninety-two years, with an average of fifty-nine years. There were twenty-three males and eleven females. Nineteen (51 per cent) were false aneurysms, sixteen (44 per cent) atherosclerotic aneurysms, and two (5 per cent) posttraumatic aneurysms. All patients presented with evidence of a mass in the neck, and only five (15 per cent) had neurological symptoms related to the aneurysm. Surgery was performed on twenty-eight carotid aneurysms. Resection and patch angioplasty was employed for eighteen aneurysms, resection with graft replacement for six, and resection and ligation of the internal carotid artery for four. Postoperative neurologic deficits developed in three patients (11 per cent), and one of these died. There was one other operative death due to acute myocardial infarction (operative mortality, 7 per cent). Nonoperative treatment was employed when the patient had other associated high risk disease or a small asymptomatic aneurysm.