Percutaneous transluminal angioplasty (PTA) was carried out 43 times for 40 lesions in 38 cases of atheroscrelotic stenosis of the intracranial or skull base cerebral arteries. The stenotic lesions involved the middle cerebral artery in 15 cases, the basilar artery in seven cases, the internal carotid artery (petrous-supraclinoid portion) in 14 cases, and the intracranial vertebral artery in four cases. Nearly all cases were symptomatic, such as TIA or stroke, and the degree of stenosis ranged from 70 to 99 percent, with a mean of 80 percent. PTA was performed using a STEALTH balloon angioplasty catheter. In these trials, PTA was successfully performed (as indicated by a residual stenosis under 50%) 36 times. The initial success rate was 84% and stenosis was reduced from 80% to 25%. Clinical follow-up was performed from 3 to 62 months with a mean of 40 months. During this period, death due to myocardial infarction or pneumonia occurred in four cases, stroke related to previous PTA occurred in one case (due to re-stenosis) and stroke unrelated to previous PTA occurred in two cases. Angiographic follow-up was performed in 30 cases after 36 successful PTA procedures. Re-stenosis was seen in 20% of the cases, symptomatic complication occurred in 7%, and asymptomatic complications occurred in 7% of the cases. There was no mortality in this series. From analysis of complicated cases, there are several characteristic findings on the stenotic lesion. These are the stenotic lesions that located near the bifurcation, involving long segment, or showing irregular shape which is including ulcer or dissection. It is important to keep a fundamental and safe technique to reduce the complication. And besides, it is very important to keep the strict indication and to avoid the high-risk patient from a morphological point of view.