The posterior circulation gives rise to approximately 15% of intracranial aneurysms. The posterior circulation aneurysms have a higher risk of rupture than those that arise from the anterior circulation. The treatment morbidity is higher as well, whether endovascular or microsurgical methods are employed. The microsurgical clipping of posterior circulation aneurysms has declined and endovascular coiling has increased. Aneurysms selected for microsurgical clipping have broad necks, aberrant branches and fusiform morphology which make them difficult to manage. The goals of endovascular management of aneurysms are to prevent hemorrhage when treating unruptured aneurysms, or avoiding rehemorrhage after a subarachnoid hemorrhage and the secondary objective is to limit the number of early strokes or other potential morbidity. The chapter discusses in detail about the open surgical techniques, the endovascular management, posterior cerebral artery, superior cerebellar artery, anterior inferior cerebellar artery, posterior inferior cerebellar artery, and vertebrobasilar aneurysms.