The activity of the vestibular nuclei is continually under cerebellar control. This control includes regulation of ongoing reflexes, vestibuloocular and vestibulospinal, and an apparent role in reflex plasticity (Chapter 8). It is the vestibulocerebellum, consisting of the flocculus, nodulus, uvula, and ventral paraflocculus (Brodal, 1974), that is related particularly closely to the vestibular system and to some of the reflexes that result when the labyrinth is activated. The vestibulocerebellum, however, is not the only part of the cerebellum that interacts with the vestibular system, as there is also a close relationship among the anterior lobe, fastigial nucleus, and Deiters’ nucleus. The details of the influence of these different parts of the cerebellum on vestibulospinal and vestibuloocular activity will be considered in subsequent chapters. Here we will describe inputs to and outputs from the cerebellum, with some emphasis on the vestibulocerebellum. Vestibulocerebellar and cerebellovestibular connections will be considered in turn, and each section, or subsection, will begin with a brief anatomical review.