This study compared parents' ratings of behavioral and emotional problems on the "Child Behavior Checklist" (Achenbach, 1991; Achenbach & Rescorla, 2001) for general population samples of children ages 6 to 16 from 31 societies (N = 55,508). Effect sizes for society ranged from 0.03 to 0.14. Effect sizes for gender were less than or equal to 0.01, with girls generally scoring higher on Internalizing problems and boys generally scoring higher on Externalizing problems. Effect sizes for age were less than or equal to 0.01 and varied across types of problems. Total Problems scores for 19 of 31 societies were within 1 "SD" of the overall mean of 22.5. Bisociety correlations for mean item scores averaged 0.74. The findings indicate that parents' reports of children's problems were similar in many ways across highly diverse societies. Nonetheless, effect sizes for society were larger than those for gender and age, indicating the need to take account of multicultural variations in parents' reports of children's problems.