We analysed the site of plaques and stenoses in the subclavian and vertebral arteries, to improve the safety of percutaneous transluminal angioplasty (PTA) in high-risk patients. These lesions were assessed on arteriograms of 35 patients with stenoses and occlusions of the subclavian and vertebral arteries; the degree of stenoses was measured. Of 19 subclavian artery stenoses 17 (89%) were in the segment proximal to the vertebral artery; 30 (79%) of 38 vertebral artery stenoses were on the medial wall. With this knowledge, a double-balloon technique using a simultaneous transbrachial and transfemoral approach for angioplasty of high-risk subclavian or combined subclavian and vertebral artery stenoses and occlusions was used successfully in seven patients. This new technique may broaden the endovascular therapeutic possibilities in the rare but dangerous situation where plaque extends directly from the stenotic subclavian artery into the origin of the vertebral artery.