In recent years neurobehavioural tests have been used increasingly in occupational settings to identify changes in cognitive function associated with exposure to neurotoxicants. Potential applications of these methods in occupational health include research, diagnosis, and screening. Applications in cross sectional research studies, involving the comparison of the performance of exposed and control groups, are well established. However, the use of such methods requires attention to factors other than exposure which may influence test performance. The validity of adapting existing test batteries for diagnosis or screening is questionable. Well developed techniques exist for diagnosis but this requires lengthy and skilled test administration and interpretation and cannot be accomplished with research batteries. The application of neurobehavioural methods for screening currently presents several difficulties. Current problems and future directions in this field are discussed.