A total of 34 stenotic lesions of the vertebral or subclavian artery were treated in 29 patients using percutaneous transluminal angioplasty (PTA). Seventeen patients were followed angiographically for up to 2 years after PTA. Of 17 patients, five (29.4%) had restenosis which developed between 3 and 6 months after the procedure. Of these patients, two were treated by repeat angioplasty uneventfully, two were treated by surgical reconstruction, and the fifth is being observed without treatment while the patient remains asymptomatic. Neointimal fibromuscular hyperplasia as seen in the surgically resected specimens was thought to be the major cause of restenosis after PTA. Indications of PTA for vertebrobasilar and subclavian artery restenosis are discussed.