Percutaneous transluminal angioplasty (PTA) was performed in 45 patients with a manifest subclavian steal syndrome. Thirty-five of those patients were subjected to follow up examinations over a period of 6 to 18 months. Five patients suffered from severe restenosis and were treated again. Two thirds of the patients benefited from the treatment. PTA of the proximal vertebral artery was performed in 15 patients with bilateral occlusive lesions of the extracranial vertebral arteries. In 13 of these cases the neurological and the vascular states of the patients were regularly reexamined, 8 showed a marked improvement. During the 2 to 25 month observation period (average 15 months post-PTA) reocclusion was observed in only two cases. These showed no recurrent neurological sequelae. Forty-three consecutive patients with acute vertebro-basilar or basilar occlusion received intraarterial fibrinolytic therapy with streptokinase or urokinase. Twenty-three of these had presented severe deficits at the beginning of therapy (e.g. complete tetraplegia, comatous state for more than 6 hours). None of this group survived. By contrast the 20 other patients in this group presented with incomplete fluctuating or progressive motor deficits. None was comatous for more than 6 hours. Fourteen patients (33% in this group) survived. Local intraarterial fibrinolytic therapy is the only therapy successful in the treatment of progressive stroke from vertebro-basilar thrombosis.