OBJECTIVES: In order to clarify the effect of lead on higher cerebral functions, lead-exposed workers (Pb group) and controls were examined for event-related potentials. SUBJECTS AND METHODS: Fourteen lead-exposed workers with a mean age of 57.1 yr (SD=4.27, range 48-64; lead concentration of whole blood ranged from 33 to 106 microg/dl with a mean of 58.6 and SD 28.6 microg/dl) and 19 age-matched control workers with a mean age of 57.3 yr (SD=4.80, range 48-65) were examined. Visual P300 was recorded by button pushing to the target image (minute checkerboard pattern, 20%), and the NO-GO potential by no button pushing to the target image (same as above, 50%). RESULTS: Latencies of P300 in the Pb group (475+/-46.0 ms) were significantly delayed compared with those in controls (407+/-42.4 ms, p<0.01 by Student's t test). Amplitudes of the NO-GO potential in the Pb group (4.59+/-2.04 microV) significantly increased compared with those in the controls (3.18+/-1.41 microV, p<0.05). CONCLUSION: The finding suggests that lead exposure affects high cerebral functions of cognition and attention, but is unclear in suppression of movement.