Aneurysmectomy was performed in 37 patients with a traumatic aneurysm the aorta in segment III. 34 "cross-clamping" without bypass was used, 6 after preliminary transposition of the subclavian artery. 3 patients died after surgery, two of whom were more than 70 years old. 2 patients developed a paraparesis, which has in the meantime considerably improved. Hesitation to operate is justified only in older asymtomatic patients at high cardiac risk. Cross-clamping is preferable to more elaborate procedures. Preliminary transposition of the subclavian artery simplifies the proximal anastomosis and may contribute to spinal-cord protection.