The computed tomographic findings of cerebral arterial ectasia in 8 patients, of which 5 cases were angiographically documented, are reported. The ectatic arteries, located predominantly in the suprasellar and interpeduncular cisterns, appeared as serpiginous, tubular structures on the unenhanced scan. The enhanced CT scan demonstrated dense, sharply defined, homogeneous intraluminal enhancement. Until recently, the diagnosis of cerebral arterial ectasia was usually established by angiography. With introduction of CT it has become possible to noninvasively indentify and characterize this vascular disorder and its associated intracranial complications. The vertebrobasilar dolichoectasia may be diagnosed by CT as an extra-axial lesioin in the cerebellopontione angle. It enhances in a tubular fashion after intravenous injection of contrast.