The relationship between auditory evoked potentials (AEP) and the German version of Zuckerman's Sensation Seeking Scale was examined. The slope of the amplitude/stimulus intensity function (N1/P2 component) and the N1 latency were particularly studied, as these variables have been found to be potential predictors of the response to lithium prophylaxis. Thirty-three healthy subjects participated in two testing series on the first day and in a third run 3 weeks later. Binaural clicks at four intensity levels (58, 68, 78, 88 dB HL, ISI 2.1 sec) were presented in randomized order by headphone. Eighty responses were averaged at each intensity level. The pattern of correlation between the German version of the Sensation Seeking Scale and a personality inventory (FPI) supports the validity of the Sensation Seeking Scale. Only a tendency toward steeper slopes of the amplitude/stimulus intensity function (ASF) in high sensation seekers was observed in the first run. However, there was a significant interaction of sensation seeking and the test run. Only high sensation seekers showed an influence of retesting on the slope of the ASF, leading to a decrease of the slope in the second, compared with the first run. This might correspond to the psychological pattern of sensation seeking, which is characterized by a permanent need for new and exciting situations and, at the same time, by a rapid loss of interest in these situations. With regard to the N1 latency, a significant interaction of sensation seeking and lead was found. Low sensation seekers showed longer N1 latencies over the right than over the left hemisphere, a finding that accords with some psychophysiological theories on the relation between asymmetric hemispherical activation and certain psychological constructs. Our results support the view that sensation seeking is a personality feature that is closely related to certain physiological variables.