To address the need for standardized test batteries, an expert group convened by the World Health Organization (WHO) and the U.S. National Institute for Occupational Safety and Health during 1983 proposed the Neurobehavioral Core Test Battery (NCTB) to identify nervous system effects of chemical exposures in human populations worldwide. To determine the feasibility of using the NCTB in varied cultures, a cross-cultural assessment was conducted under WHO auspices. Data were collected in 10 countries of Europe, North and Central America, and Asia from over 2300 males and females who were not exposed to chemicals at work, within five age ranges between 16 and 65. Results suggest that performance on two NCTB tests (Simple Reaction Time, Benton Visual Retention) is very similar in a broad range of countries and that performance on four other NCTB tests (Santa Ana, Digit Symbol, Digit Span, Aiming) is relatively more variable from country to country, in both males and females. However, data collected from very poorly educated males in one country revealed very low performance levels suggesting that the NCTB may not provide an adequate reference group for identifying (behavioral) neurotoxic effects in such populations. More research is thus needed on evaluating neurotoxicity in poorly educated subjects.