Status marmoratus (ST) of the basal ganglia and thalamus has been observed in cases of perinatal hypoxic ischemic encephalopathy and rarely of postnatal encephalopathy. In occasional cases, the cerebral cortex is also involved. Here, we reported a 22-year-old male with a sequela of postnatal anoxic encephalopathy. He had been bedridden with severe mental retardation since he suffered anoxic encephalopathy at 3 months of age. ST was found in the cerebral cortex as well as basal ganglia and thalamus. In addition to ST, the cerebral cortex and white matter were remarkably devastated. We also performed a preliminary immunohistochemical study to investigate the process of ST formation, using antibodies against glial fibrillary acidic protein (GFAP), myelin basic protein (MBP) and synaptophysin. MBP-positive abnormal myelinated fibers were identified in the ST areas, which were not colocalized with GFAP-immunopositivity. Synaptophysin was positive in the areas of ST, which were not stained with Holzer method. These results suggest that the myelination in the early infancy damage of basal ganglia and cerebral cortex could be implicated in the formation of ST.