The clinical pictures of a left temporal lobe astrocytoma involving the hippocampal region showed a period of 27 years from ages 12 to 38 by epileptic seizures and a period of 9 years from 14 to 22 by schizophrenia-like symptoms and the following aggressive behavior during 16 years from ages 23 to 38. After a resection of the temporal lobe tumor sparing the hippocampus, transient delusions and aggressive behavior were observed. It might be considered that the hippocampus has the most suspectable relationship with the schizophrenia-like symptoms.