Complaints suggestive of impaired cognitive function often number among the adverse effects associated with exposure to toxicants, such as methylmercury, lead, and polybrominated biphenyls. The predominance of these symptoms requires that measures designed to identify deficits in learning and memory be included in the determination of an agent's neurotoxic potential. The area of learning and memory assessment is complex, and it is apparent that no single test or small subset of tests will serve to indicate all forms of impairment which might follow toxicant exposure. Rather, the identification and characterization of such dysfunction in neurotoxicity should be made on the basis of an evaluation using a battery of measures. Thus, the goals of this chapter are to review, consolidate and integrate the available literature, both human and infrahuman, on learning and memory measures in the detection and characterization of neurotoxicant exposure effects, and make suggestions for the future use of learning and memory measures in neurotoxicology. To adequately test an effect on ability to learn and remember requires a series of tests for the direct as well as the indirect effects of an agent. (Copyright (c) Johns Hopkins University Press, Baltimore. (1986).)