Paraneoplastic cerebellar degeneration (PCD) is a rare cause of profound cerebellar dysfunction. Degenerative disorders of the cerebellum can cause cognitive and behavioral changes but the neuropsychological and behavioral sequelae of PCD are not well described. In this article, we detail selective frontal-executive disturbance, psychomotor slowing and affective change in a patient with PCD in whom there is no apparent extracerebellar involvement. The pattern of deficits suggests that PCD may be clinically dissociable from other forms of paraneoplastic encephalitis and correspond closely with the recently proposed “cerebellar-affective syndrome.” The results underline the importance of the cerebellum in regulating cognitive function.