This study demonstrates the utility of using BARS to assess cognitive and motor performance in Thai children. Overall test-retest reliability is acceptable although alternate forms need further refinement to improve their comparability. As for most neurobehavioral tests, age, sex, and parental education influence performance and must be controlled for in the design and analysis of these tests. Continuing cross cultural validation of the BARS will allow data aggregation for the purpose of assessing the effects of world wide neurotoxicant exposure on child development.