The origin of the vertebral artery is a frequent site for the development of stenosing lesions. The flow deficit caused by the stenosis of one vertebral artery is normally compensated for by intracranial anastomosis between the carotid and basilar arteries or by the opposite vertebral artery. A number of patients, however, have inadequate intracranial anastomosis and hypoplasia or stenosis of the opposite vertebral artery, and symptoms of brain ischemia develop. We describe here four cases in which a new technique, a subclavian vertebral artery autogenous vein bypass graft, was used to deal with the diseased segment of the vertebral artery. Transient postoperative problems included lymphocele and Horner syndrome. All four bypasses were patent at the time of angiography one week postoperatively. All four patients were relieved of symptoms of vertebrobasilar insufficiency.