This report describes for the first time the successful use of transluminal balloon-catheter dilation (angioplasty) for high-grade basilar artery atherosclerotic stenotic lesions in two patients with frequent, severe, progressing symptoms that were unresponsive to anticoagulant therapy. Excellent angiographic and short-term clinical results have been obtained. These results and the relative frequency of these lesions justify further evaluation of this approach.