Rostral posterior circulation bypass is technically challenging. Pretemporal approach has been reported to facilitate the bypass procedure within the oculomotor-tentorial triangle. However, bridging veins converging into cavernous sinus at the temporal pole usually need to be sacrificed.To report operative nuances of rostral posterior circulation bypass with an emphasis on preserving the Sylvian veins and enlarging surgical space, we use a double-barrel superficial temporal artery-posterior cerebral artery/superior cerebellar artery anastomosis using an epidural pretemporal transcavernous approach.A 54-year-old man had a subarachnoid hemorrhage attack 1 month before the admission. A flow-related anterior spinal artery aneurysm with bilateral vertebral artery occlusive diseases was indicated. The aneurysm was difficult to be directly treated, either by the endovascular approach or by the microsurgical clipping. A double-barrel superficial temporal artery-superior cerebellar artery/posterior cerebral artery bypass was performed using an epidural pretemporal transcavernous approach.The anastomoses were successfully accomplished in a large surgical space. The patient recovered well with no events, except a transient right cranial nerve III paralysis. The aneurysm was demonstrated to be completely regressed at the 5-month follow-up.An epidural pretemporal transcavernous approach could be an alternative for rostral posterior circulation bypass.Copyright © Congress of Neurological Surgeons 2022. All rights reserved.