Patients with subclavian steal syndrome present with symptoms of vertebrobasilar ischaemia. Although angiography has traditionally been used to confirm the diagnosis of subclavian steal and plan reconstructive surgery in symptomatic patients, duplex ultrasonography now offers rapid diagnosis and also permits examination of the other extracranial vessels. The treatment of subclavian steal syndrome is surgical. Extra-anatomic bypass procedures are used to increase inflow to the subclavian artery, abolishing the steal phenomenon. Carotid-subclavian bypass or transposition and subclavian-subclavian or axilloaxillary bypass are the procedures of choice; selection is governed by the presence of coexistent carotid artery disease. Percutaneous transluminal balloon angioplasty of the subclavian artery is an alternative treatment, although the long-term patency rate is inferior to that of extra-anatomic bypass.