We analyzed the clinical features of symptomatic posterior cerebral artery (PCA) stenosis in 6 patients selected from 15 patients with angiographically documented PCA atherostenosis occurring during a 7-year period. Transient ischemic attacks (TIAs) were the major presentation in 5 patients. A homonymous visual field defect was present in 2 patients. TIA symptoms were predominantly visual or sensory, or both. The most common visual symptom was difficulty seeing to one side. One patient saw flashing lights. Sensory spells were always paresthetic, usually involving the arm and hand and occasionally the face and leg. Three patients had visual and sensory spells together. Two patients with a visual field defect had calcarine infarcts found by computed tomography. All patients were treated with warfarin. During follow-up (4 months to 4 years), no patient had a new stroke in the PCA territory, and only one continued to have TIAs. PCA atherostenosis is rarer then PCA embolic occlusion. In contrast to those with PCA embolism, our patients with PCA atherostenosis had more TIAs and fewer infarcts. The clinical features of PCA stenosis--preponderance of visual and sensory TIAs--distinguish this vascular lesion from stenosis of the middle cerebral artery.