This chapter provides detail description of Posterior circulation aneurysms. Chapter has 10 well illustrated diagrams and pictures. Aneurysms of the posterior circulation, microsurgical anatomy of posterior circulation aneurysms, incidence of posterior circulation aneurysms, clinical presentation of posterior circulation aneurysms, diagnostic studies of posterior circulation aneurysms, surgical approaches for posterior circulation aneurysms, management of posterior circulation aneurysms, subtemporal approach, Pterional-trans-Sylvian approach, orbitozygomatic and extended orbitozygomatic approach, alternative surgical strategies, endovascular management, endovascular obliteration, management of giant posterior circulation aneurysms are described in detail. One table is included to highlight surgical approaches for posterior circulation aneurysms. 56 references are included at the end of the chapter to facilitate further reading.