[3H]Kainic acid binding sites were measured post mortem in the putamen and prefrontal cortex areas from 10 control subjects and 12 schizophrenic patients. A 25-50% increase in [3H]kainic acid binding was observed in the medial frontal (Brodmann areas 9, 10 and 46) and eye-movement areas (8), but not in the other regions of schizophrenic brains. No significant correlation between the binding and either age at death, storage of the brains, duration of illness or neuroleptics-free period was observed. These findings suggest that a dysfunction of cortical excitatory amino acidergic transmission may be involved in schizophrenia.