The present autopsy study was performed to examine whether long-term antipsychotic medication of schizophrenics promoted pathologic transition to Alzheimer's disease (AD) of the brain. Immunohistological staining of the hippocampal region with anti-human tau antibody was used to examine the degree of AD pathology in seven schizophrenic patients who had received long-term antipsychotic medication and in seven controls. The schizophrenic patients showed no significant difference from the controls for the number of tau-positive neurons. Additionally, the total amount of antipsychotic drugs for schizophrenic patients was calculated by using of chlorpromazine equivalents. No significant correlation between the total amount of antipsychotic drugs and the degree of AD pathology was observed. The long-term antipsychotic medication of these schizophrenics did not promote the development of AD pathology in the brain.