An autopsy case of adult neuronal ceroid-lipofuscinosis was examined. The clinical picture was characterized by gait disturbance, bulbar palsy and dementia. Histopathologically, diffuse neuronal loss was found throughout the central nervous system. The remaining neurons, predominantly in the motor nuclei of the spinal cord and brain stem, were swollen with storage material. Observed under the electron microscope the storage material showed various ultrastructures, such as lipofuscin-like bodies, pleomorphic lipid bodies, curvilinear profiles and finger-print profiles, in different regions of the central nervous system. In the ballooned neurons of the spinal anterior horn, many membranous cytoplasmic bodies and curvilinear profiles were intermingled within the same cell and were continuous with each other. Biochemically, N-acetyl neuraminic acid content was significantly increased in the spinal anterior horn. These findings suggest the localized increase of ganglioside in that region.