The aim of this preliminary study was comparison of quantitative EEG pattern of schizophrenic patients treated with neuroleptic drugs with that of matched healthy control subjects. Gender differences of quantitative EEG patterns were found both in schizophrenic patients and healthy subjects. The di1Terences of EEG pattern between schizophrenic patients and control subjects were evidenced mainly in frontal areas. The influence of type of neuroleptic on EEG spectral analysis results in schizophrenic patients was confirmed. The increasing of interhemispheric asymmetries of brain electric activity was observed in male and female schizophrenic patients and in male healthy subjects.