Severe arteriosclerotic changes often prevent navigating a guiding catheter into an appropriate position during aneurysm embolization. A basilar superior cerebellar artery aneurysm was found in a patient who had had subarachnoid hemorrhage 6 months previously. We selected embolization for this aneurysm using Guglielmi detachable coils (GDC) because of its highly located position from the dorsum sellae. We could not introduce a guiding catheter into the distal portion of the vertebral artery because of severe arteriosclerotic changes and it easily prolapsed into the aorta when a microcatheter was navigated through the guiding catheter positioned in the proximal vertebral artery. We were able to successfully perform embolization of the aneurysm by fixing a guiding catheter at the origin of the left vertebral artery with a goose neck snare wire introduced from the left brachial artery. The authors emphasize that a snare wire is useful not only for retrieval of foreign bodies but also for fixing a guiding catheter during aneurysm embolization, especially in which prolapse of the guiding catheter may cause a serious complication.