TRANSIENT ISCHEMIC ATTACKS (TIAs) of the posterior circulation are associated with a significant risk of subsequent infarction, particularly when caused by stenotic lesions in the intracranial portion of the vertebral artery (VA). Eight patients who had persistent posterior circulation TIAs despite receiving maximal medical therapy (including anticoagulation) and who had angiographic evidence of severe stenosis of the proximal intracranial VA with poor collateral flow were treated by endarterectomy of the intradural VA. Their ages ranged from 52 to 65 years. Five of these operations were performed via the far lateral approach. In all patients, the contralateral VA was hypoplastic or occluded, or ended in the posterior inferior cerebellar artery. Postoperative angiograms showed that the arteries of five of the patients were widely patent, one was improved but still stenotic, and two were occluded. The latter two patients subsequently underwent thrombectomy, after which the artery was patent in one patient and remained occluded in the other. After surgery, the TIAs of seven patients were relieved completely, and the patients were neurologically intact. The patient with persistent occlusion ultimately had moderate disability. Complications included the two cases of thrombotic occlusion that required a second operation, three cases of communicating hydrocephalus that required lumboperitoneal shunts, and two cases of transient dysfunction of the 9th and 10th cranial nerves. Suitable patients with persistent posterior circulation TIAs refractory to medical therapy who have appropriate angiographic evidence of proximal VA stenosis and poor collateral flow may benefit from endarterectomy of the intradural VA. Surgical exposure using the far lateral approach provides much better access to the intradural portion of the VA for endarterectomy than the standard suboccipital approach.