Accurately measuring blood pressure (BP) requires choosing an appropriate BP cuff size.This study examined trends in mid-arm circumference (mid-AC) and in the distribution of appropriate BP cuffs using 1999-2010 National Health and Nutrition Examination Survey (NHANES) data.NHANES uses a complex multistage probability sample design to select participants who are representative of the entire civilian, noninstitutionalized US population. The analytic sample consisted of 21 350 participants aged between 3 and 19 years at the time of examination. The mean mid-AC and the percentage of children requiring recommended BP cuff sizes were analyzed across survey years and by sex, age, race/ethnicity, and age-specific and sex-specific BMI categories.During NHANES 1999-2010, the overall trend in mean mid-AC in cm for boys and girls was not significant. During NHANES 2007-2010, 24% of boys aged between 9 and 11 years, 53% of boys aged between 12 and 15 years, and 89% of boys aged between 16 and 19 years required a standard adult cuff or larger to be cuffed correctly. Corresponding estimates for girls were 22, 48, and 57%, respectively. During NHANES 2007-2010, 30.4% of obese boys and 24.3% of obese girls required a large adult cuff and 2.1% of obese boys and 0.9% of obese girls required a thigh cuff for appropriate cuffing.During NHANES 2007-2010, 20% of boys and girls as young as 9-11 years required a standard adult cuff to be cuffed appropriately. In addition, approximately one-third of obese participants required adult large BP cuffs to be cuffed appropriately.