The cerebellar peduncles are large axon bundles that interconnect the cerebellum with other areas of the nervous system. It is now well established that the cerebellum contains one of the highest densities of CB1 receptors in the mammalian brain. It appears that the primary mode of action of endocannabinoids in the cerebellum is self-regulation by Purkinje cells via retrograde signaling back to the presynaptic terminals that innervate them. In terms of behavioral outcomes, several studies have shown that cannabinoid administration in humans is associated with alterations in temporal processing and psychomotor performance, both of which are at least partly cerebellar-mediated. In addition to alterations in cerebellar-mediated behavioral outcomes, numerous studies have shown that patients with schizophrenia exhibit abnormalities in cerebellar structure and metabolism. To recapitulate, the current chapter has attempted to synthesize known literatures regarding the effect of cannabinoids on cerebellar function and the role of the cerebellum in schizophrenia.