Performing neurobehavioral assessments of occupationally relevant solvents and chemicals was discussed. The goals of human neurobehavioral research were summarized. Human neurobehavioral research is conducted to establish basic, pharmacokinetic, physiological, and neurobehavioral effects of chemicals under simulated laboratory or actual workplace conditions, test the adequacy of exposure limits for preventing neurotoxic effects, identify those aspects of human performance that may be impaired by exposure to toxic agents which could increase the risk of unsafe job performance, investigate the effects of different exposure patterns on behavior, and examine possible interactions between chemical exposure and other workplace variables such as physical workload. Differences between laboratory and worksite neurobehavioral studies were discussed. The discussion considered differences between experimental approaches and designs and exposure conditions. Chemicals, metals, and drugs that have been examined in neurobehavioral studies were described. Twenty nine different chemicals of which 15 are industrial solutions have been studied individually or in combination. Toluene (108883) has been the chemical most frequently studied in laboratory settings. Lead (7439921), mercury (7439976), and carbon-disulfide (75150) have been the chemicals most frequently studied in the workplace. Limitations in performing human neurobehavioral research included having to use restricted dose ranges, and difficulties in defining subclinical changes in performance. Strategies that have been developed to address these problems included developing tests that are more sensitive than the traditional toxicological tests that emphasize lethality and pathological changes and using reference substances with similar biological effects. The review summarized data obtained in 83 laboratory studies and 185 studies over the past 25 years. The studies focused on nine endpoints, including fatigue, mood, symptomatology, and performance of cognitive and motor tasks.