To clarify the cognitive significance of event-related potential (ERP) abnormalities in schizophrenia, we examined the relationships of amplitudes and latencies of ERP components with performance on neuropsychological tests in schizophrenic patients. Twenty patients underwent the Trail Making B Test (TM-B), which is sensitive to frontal lobe dysfunction, and the logical memory, verbal paired-association, and visual reproduction subtests of the Wechsler Memory Scale (WMS), which are sensitive to temporal lobe dysfunctions, and ERP recordings during performance of an oddball auditory discrimination task. Pearson product-moment correlations indicated that an increased P200 amplitude was correlated with poor performance on the TM-B, whereas a decreased P300 amplitude was correlated with poor performance on the verbal paired-association subtest of the WMS. These findings suggest that a P200 abnormality represents the frontal lobe dysfunction, and a P300 abnormality represents the left temporal lobe dysfunction in schizophrenia.