True aneurysm of the subclavian artery is extremely rare and atherosclerosis is the most common cause. Syphilis, tuberculosis, and cystic medial necrosis are less often the cause. Their exact prevalence in the general population is unknown. These aneurysms can rupture, thrombose, embolize or cause symptoms by local compression. In reviewing the literature the great latency of the disease, high complication rate at presentation and the significant incidence, concomitant aneurysms elsewhere are emphasized. Duplex scanning followed by angiography should be performed in order to establish the diagnosis and to plan the operation. Elective surgical treatment is associated with little risk to the patient and avoids the need for emergency operations. Two cases of surgically treated true subclavian aneurysms are presented with review of the English language literature on the subject.