Neuronal ceroid-lipofuscinosis was diagnosed in a young adult domestic short-haired cat euthanatized because of severe progressive neurologic disease. Clinical signs included blindness, seizures, and decreased mentation. An autofluorescent pigment, identified as ceroid-lipofuscin by electron microscopy and staining properties, was found within neurons of the central and peripheral nervous systems. A diffuse reactive astrocytosis accompanied by multifocal microgliosis was visible in all areas of the brain. Retinal atrophy with intraneuronal lipopigment accumulation was also identified. Contrary to the human neuronal ceroid-lipofuscinoses, pigment deposition appeared to be restricted to neural tissues.