The purpose of this study was to establish sex-specific criterion-referenced standards for pedometer-determined physical activity related to body mass index (BMI)-defined weight status among youth. We analyzed data from 7-16-year-old boys (n = 338) and girls (n = 337) and used pedometer-assessed physical activity and anthropometric data to derive average steps/day and BMI. Sex-specific criterion-referenced standards for steps/day relating to healthy weight and overweight/obese were determined using the contrasting groups method. Healthy weight children took more steps/day than overweight or obese (boys: 14,413 vs. 12,088, and girls: 12,562 vs. 10,114, respectively; p less than 0.001). The optimal BMI-referenced cut-point emerging from our sample was 16,000 steps/day for both boys and girls. Our results and those reported elsewhere suggest that youth take insufficient pedometer-determined steps/day to avoid becoming overweight. (Contains 2 tables.)