Recent studies into the neurotoxic effects of chemicals on workers are reviewed. Several aspects of neurotoxicological research which are discussed include the identification of confounding factors, the significance of prenatal exposure to potential neurotoxins, the selection of a test battery to measure neurological functions, the relationship of research findings to actual occupational conditions, and the application of neurological and behavioral performance tests as part of an on site health screening program. An eye tracking technique is described which has potential use as a sensitive test for early nervous system dysfunction. The results of a NIOSH health survey of pesticide workers exposed to leptophos (21609905) and other chemicals in one facility are presented. Results indicate that a substantial number of those examined had neurological, electromyographic, electroneurographic, and psychological performance abnormalities, and that the workers were adversely affected by conditions that could have been prevented by more careful medical surveillance, work practices, and engineering controls. The authors conclude that the support of neurotoxicology research will result in information useful in detecting early, reversible, functional changes in workers experiencing long term exposure to industrial chemicals.