A 37-year-old female was admitted to our hospital because of progressive dementia and gait disturbance. She was healthy until 34 years of age when she had difficulty in walking and memory disturbance with personality changes. At age 36, she developed urinary incontinence and dementia. The neurological examination demonstrated euphoric mental state, emotional incontinence, severe dementia, paraplegia, dysmetria, choreic movements in both arms and urinary incontinence. Diffuse hyperreflexia and bilateral Babinski signs were observed. Routine laboratory examination showed slightly increased erythrocyte sedimentation rate and alkaline phosphatase. Electroencephalogram revealed diffuse irregular slow waves. X-ray film of the ulnar bone revealed osteoporotic and cystic lesions. The biopsy of the left tibial bone showed a specific membranous cystic structure. Computerized tomography (CT) of the brain showed symmetric, diffuse low density areas in the cerebral white matter and severe atrophy of the cerebellum. T2-weighted magnetic resonance imaging (MRI) revealed diffuse high intensity areas in the cerebral white matter. The present case is characterized by diffuse changes in cerebral white matter and cerebellar atrophy, which have been never reported in Nasu-Hakola disease. The diffuse cerebral white matter changes shown by CT and MRI appear to indicate that this patient is the first case of leukodystrophy of sudanophilic type since the original case reported by Nasu et al.