Auditory brain stem responses (ABSR) were examined systematically both in normal and schizophrenic subjects. All ABSR wave forms were evoked by click stimuli, which were delivered binaurally through headphones both to normal subjects and to a nondeteriorated group of schizophrenics. However, in the group of schizophrenics with marked deterioration of personality, not all wave forms were elicited, and the amplitudes were low. The characteristics of the ABSR wave forms correlated well with the clinical symptoms of the schizophrenic illness. The cause of these ABSR wave form changes in schizophrenics is discussed.