Event-related potentials (ERPs) were examined in 16 college students who had high scores on the Schizophrenia Scale of the MMPI (HSS) but were without a hereditary disposition for major psychiatric disorders. 32 sex- and age-matched college students were used as controls. Subjects whose T scores were higher than 70 were designated the HSS subjects. ERPs were recorded during an auditory oddball task. Although neither the P300 latencies nor the P200 latencies differed between the two subject groups, the amplitudes of P300 to rare stimuli and P200 to frequent stimuli were lower in the HSS subjects than in the controls. These results suggest that deficits, both in the P300-related cognitive function to rare relevant stimuli, as well as matching and/or the comparison process for irrelevant frequent stimuli, may be present in HSS subjects. The HSS subjects, especially those with a combination of P300 and P200 deficits, even though without a hereditary diathesis for schizophrenia, may constitute one type of high-risk group.