Measurement and distribution of systolic and diastolic blood pressure and related health risk factors in the National Longitudinal Study of Adolescent Health (Add Health) were compared with data from the National Health and Nutrition Examination Survey (NHANES) 2007-2008. Sociodemographic patterns of blood pressure, prevalence of hypertension, and measurement characteristics in Add Health were also examined. Prevalence of hypertension (20.88%) in Add Health was significantly higher than that in NHANES (4.60%). This difference was only partially explained by body mass index and waist circumference and could reflect different measurement techniques, sample composition differences, or masked hypertension.