The most important function of the cerebellum may be to coordinate motor function so that movements can be performed smoothly, but there are others. It has been shown that the cerebellum is involved in certain aspects of cognition and changes in affect. Also verbal deficits can be found after cerebellar lesions. The cerebellar cognitive affective syndrome is described, and the evidence for its existence discussed; in particular the use of neuroimaging studies. Different areas of the cerebellum have been identified as serving the various functions, and also their connections to the relevant parts of the cerebral cortex. Certain conditions merit special attention. The function of spatial navigation needs a major contribution from the cerebellum, and the problems of autism and impaired cognition are no doubt related to the enlarged cerebellum described in this disorder. The cognitive defects found in children with cerebellar ataxia supports its role in learning, and so does the study of music.