We present a case of infantile leukodystrophy with some sudanophilic features. A normally developed male infant did well until age 15 months. Then he had episodes of myoclonus, reversal of intellectual development, rigidity with decerebrate posturing and epilepsy, which became severe. He died at age 7 years, 10 months. On autopsy, the brain was normally developed, but there was severe demyelination and gliosis throughout the white matter; the cerebellar cortex showed atrophy. The striking, unexpected finding was the presence of numerous Alzheimer's tangles containing paired helical filaments in electronmicroscopic examination, not only in the cerebral cortex but also in the brainstem, basal ganglia, and hypothalamus including the nucleus basalis of Meynert. Other unusual findings were hyperostosis of the skull and the appearance of macrophages containing PAS-positive granules in the reticuloendothelial system in many organs.