Aneurysms arising from the distal basilar artery(BA) and relating to the origin of the superior cerebellar artery (SCA), posterior cerebral artery (PCA) account for more than 15% of all intracranial aneurysms and more than one-half of all aneurysms occurring in the vertebrobasilar circulation. The anatomic complexity of the interpeduncular cistern is directly related to the dangers of surgical manipulation in this region and it is undoubtedly difficult to operate on a distal basilar aneurysm which located deep in a very narrow operative field restricted by unremovable neural and vascular architectures. Although we can not choose no single operative approach suitable to this area because the indivisual patient's vascular, neural and bony anatomy is widly variable, using the modified transsylvian approach with orbitozygomatic resection the distal basilar artery aneurysms could be seen and clipped easily by upward and oblique viewing from below through the wide operative space consisting of the less retracted intracarotid artery, middle cerebral artery and oculomotor nerve. We have operated 64 distal basilar artery aneuysms. Among them, 27 patients were approached using the modified transsylvian approach with orbitozygomatic resection. The operative procedure is presented in detail and compared with other surgical approaches.