A prediction model, developed in the Framingham Heart Study (FHS), has been proposed for use in estimating a given individual's risk of hypertension. We compared this model with systolic blood pressure (SBP) alone and age-specific diastolic blood pressure categories for the prediction of hypertension. Participants in the Multi-Ethnic Study of Atherosclerosis, without hypertension or diabetes mellitus (n=3013), were followed for the incidence of hypertension (SBP ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg and/or the initiation of antihypertensive medication). The predicted probability of developing hypertension among 4 adjacent study examinations, with a median of 1.6 years between examinations, was determined. The mean (SD) age of participants was 58.5 (9.7) years, and 53% were women. During follow-up, 849 incident cases of hypertension occurred. The c statistic for the FHS model was 0.788 (95% CI: 0.773 to 0.804) compared with 0.768 (95% CI: 0.751 to 0.785; P=0.096 compared with the FHS model) for SBP alone and 0.699 (95% CI: 0.681 to 0.717; P<0.001 compared with the FHS model) for age-specific diastolic blood pressure categories. The relative integrated discrimination improvement index for the FHS model versus SBP alone was 10.0% (95% CI:-1.7% to 22.7%) and versus age-specific diastolic blood pressure categories was 146.0% (95% CI: 116.0% to 181.0%). Using the FHS model, there were significant differences between observed and predicted hypertension risks (Hosmer-Lemeshow goodness of fit: P<0.001); recalibrated and best-fit models produced a better model fit (P=0.064 and 0.245, respectively). In this multiethnic cohort of US adults, the FHS model was not substantially better than SBP alone for predicting hypertension. © 2010 American Heart Association, Inc.