The authors describe an autopsy case of glioblastoma occurred after 38 years received lobotomy. The patient was a 72 year-old male, who received lobotomy at 34 year old against schizophrenia. CT scan taken at 72 year old showed irregular low density areas without mass effect in the bilateral frontal white matter adjacent to the anterior horn. After 4 months, the signs of intracranial hypertension were observed and his consciousness was disturbed abruptly. CT scan revealed ring enhancement with marked mass effect in the left frontal lobe. A biopsy specimen from the tumor showed a picture of anaplastic astrocytoma. Family rejected the remission maintenance treatment. The patient died 3 months later the onset. At autopsy, a large tumor occupied in the left frontal lobe was recognized. The tumor demarcated poorly from the cerebral tissue and invaded into the left anterior cingulate gyrus and the corpus callosum. Histologically, tumor cells composed of fibrillary, gemistocytic and multinucleated astrocytes. GFAP, NSE and vimentin were found in large cells. Histological diagnosis was glioblastoma. It was suggested that the tumor occurred from the region around a cyst of prefrontal lobotomy in the left frontal lobe. In the right frontal lobe, a large cyst in size of 30-18 mm was present in the centrum semiovale. The wall of cyst was composed of layer of glial scar tissue. The origin of the cyst was discussed.