Occupational exposures to neurotoxic chemicals were discussed. The epidemiological aspects of occupational exposure to neurotoxic agents were considered. More than 850 chemicals for which evidence of neurotoxicity exists have been used in the workplace. Workplace exposures may occur by multiple routes including cutaneous, oral, and inhalation exposure. Although inhalational exposures were the most easily measured and form the basis for most estimates of chemical exposure in occupational research, oral and cutaneous exposures should not be neglected. Twenty two chemical groupings containing ten or more neurotoxic chemicals and industries where these chemicals have been used were listed. The major usage categories included solvents, pesticides, fertilizers, chemical synthesis, metal production, plastics, textiles, pharmaceuticals, photography, glass manufacturing, and automobile manufacturing. A total of 120 nervous system effects have been identified as resulting from exposure to neurotoxic chemicals. Thirty five of these have been classified as neurobehavioral. Functional tests of neurotoxicity in humans were reviewed. General approaches for workplace testing of neurobehavioral effects were described. Occupational neurobehavioral research on industrial chemicals was discussed. Most studies have focussed on solvents and heavy metals. Exposure to these agents has produced changes in psychomotor performance, intelligence, personality, and nerve conductance velocity. Steps needed to perform a workplace neurobehavioral evaluation were described. Debriefing and problem remediation following a workplace neurobehavioral research project were discussed.