A single trial analysis of event-related potentials (auditory odd-ball paradigm) of 20 schizophrenics was performed in comparison to matched healthy controls. The purpose of the study was to test the hypothesis that in schizophrenia the well-known P300 amplitude reduction of averaged event-related potentials is due to fewer elicited single trial P300 waves. The results of the present study support this finding of our previous exploratory investigation and point to the view that schizophrenics reveal basal disturbances in information processing due to inadequately elicited electrophysiological responses to target stimuli.