Neurovascular diseases of the posterior circulation represent a major cause of morbidity and mortality, which is due in large part to the eloquence of the brainstem and cerebellum and the anatomical constraints of the posterior fossa. A sound understanding of posterior circulation vascular anatomy builds the foundation for the accurate diagnosis and appropriate management of posterior fossa neurovascular ischemic and hemorrhagic disease. This chapter begins with a brief overview of vertebral and basilar arterial anatomy, followed by a comprehensive discussion of brainstem and cerebellar vascular topography in the setting of ischemic stroke. The epidemiology, clinical presentation, prognostic factors,