A significant part of patients with carotid artery stenosis is operated on without preoperative angiography, to reduce the risks and cost of such examination. Duplex ultrasound often cannot reliable visualise the proximal parts of the aortic arch vessels. We evaluated the ability of duplex ultrasound to identify those types of lesions and ascertain their prevalence. We analysed retrospectively carotid duplex scans and carotid angiography in 448 carotid arteries. 17 significant proximal lesions (3.89%) were identified on the duplex scan and confirmed by angiography. Lesions of the proximal parts of the aortic arch vessels are rare and may be reliably detected by duplex ultrasound.