Eight patients with transient attacks of cerebrovascular insufficiency were treated by reconstruction of an atheromatous stenosis at the origin of a vertebral artery. The technique was relatively simple and safe, and was effective in relieving symptoms. Previous reviews suggest that the symptoms of vertebrobasilar insufficiency tend to be persistent, frequent and distressing, and that they can be a prelude to brain stem infarction. The collateral circulation to the vertebrobasilar system may be restricted by anatomical variations and by disease, particularly affecting the circle of Willis. Bilateral vertebral artery disease can cause appreciable ischæmia even without associated carotid artery disease. Carotid endarterectomy is not particularly effective in relieving vertebrobasilar symptoms. Vertebral artery reconstruction appears to be the appropriate treatment for vertebrobasilar insufficiency