To compare parent-reported problems for children in 12 cultures. Child Behavior Checklists were analyzed for 13,697 children and adolescents, aged 6 through 17 years, from general population samples in Australia, Belgium, China, Germany, Greece, Israel, Jamaica, the Netherlands, Puerto Rico, Sweden, Thailand, and the United States. Comparisons of 12 cultures across ages 6 through 11 and 9 cultures across ages 6 through 17 yielded medium effect sizes for cross-cultural variations in Total Problem, Externalizing, and Internalizing scores. Puerto Rican scores were the highest, while Swedish scores were the lowest. With great cross-cultural consistency, Total and Externalizing scores declined with age, while Internalizing scores increased; boys obtained higher Total and Externalizing scores but lower Internalizing scores than girls. Cross-cultural correlations were high among the mean item scores. Empirically based assessment provides a robust methodology for assessing and comparing problems reported for children from diverse cultures. Age and gender variations are cross-culturally consistent. Although clinical cutoff points should not necessarily be uniform across all cultures, empirically based assessment offers a cost-effective way to identify problems for which children from diverse cultural backgrounds may need help.