Background: African-American and Latino children living in neighborhoods with a low-socioeconomic index are more at risk of obesity-associated metabolic disease than their higher socioeconomic index and/or white peers. Currently, consistent and reliable questionnaires to evaluate nutrition and physical activity knowledge in these children are needed. Objective: The purpose of this study was to develop nutrition and physical-activity knowledge questionnaires that would be reliable and internally consistent when used with African-American and Latino children living in inner-city communities. Methods: A total of 112 children, 8-11 years of age, identified by a parent as being either African-American or Latino, were recruited and administered questionnaires. Internal consistency, one measure of reliability, was assessed by calculating the Cronbach's alpha of test scores. Test-retest design was used to assess the reproducibility by calculating the intraclass correlation coefficients and Pearson correlation coefficients. Results: The nutrition knowledge and physical-activity knowledge indices had alphas of 0.80 and 0.77, respectively. Both questionnaires had excellent test-retest reliability, with intraclass correlation coefficients of 0.82 and 0.83, respectively. The questionnaires had reliable alphas for both African-American and Latino 8-11yr old children, for both boys and girls. Multiple linear regression analysis, with ethnicity, gender, and grade entered simultaneously into the models, showed that nutrition knowledge and physical activity knowledge scores were not significantly related to these three variables. Application to Child Nutrition Professionals: The questionnaires used in this study are internally consistent and may be used to evaluate nutrition and physical-activity knowledge in African-American and Latino children in grades 3, 4, and 5. Additional evaluations would be needed to determine if these tools are also reliable for children from other ethnicities, ages, and grades. (Contains 5 tables.)