OBJECTIVE: Functional neuroimaging studies have identified a role for the cerebellum in the neuropsychology of schizophrenia. Few studies, however, have examined the relationship between cerebellar size and neuropsychological functioning in schizophrenia. The authors’ goal was to examine this relationship in patients and healthy comparison subjects. METHOD: Total cerebellar volume was computed from magnetic resonance images in 48 male and 33 female patients experiencing a first episode of schizophrenia and in 14 male and nine female healthy comparison subjects. Patients and comparison subjects completed a comprehensive neuropsychological assessment encompassing six domains of functioning: executive, motor, language, visuospatial, memory, and attention. A global domain of functioning was computed as the mean of these six domains. RESULTS: Larger cerebellar volume correlated significantly with better global functioning in healthy subjects but not among patients with schizophrenia; this relationship was significantly stronger in healthy subjects than in patients. Additional analyses revealed significant associations between cerebellar volume and visuospatial, executive, and memory functions in healthy volunteers but not among patients. CONCLUSIONS: The cerebellum plays a role in higher cognitive functions in healthy individuals, and normal associations between cerebellar size and function are absent in patients experiencing a first episode of schizophrenia. These findings are consistent with neurobiological models implicating the cerebellum in the pathogenesis of schizophrenia.