Blood pressure (BP) readings taken by Omron HEM-907XL were compared with the results obtained using sphygmomanometer (HgS) in 509 individuals using 2002 Association for the Advancement of Medical Instrumentation (AAMI) criteria. With the exception of diastolic BP in youth ages 13 to 19 years (mean difference, -1.77 mm Hg; standard deviation, 8.65), the Omron device met the criteria. Agreement for hypertension (BP >or=140/90 mm Hg) was above chance (kappa=0.68) and, compared with HgS, Omron underestimated the prevalence of hypertension by 2.65%. The Omron and HgS measurements were highly correlated (r=0.94 for systolic BP and r=0.83 for diastolic BP). Both increased systolic and diastolic BP decreased device agreement (beta-coefficient=-0.10872, P<.0001; beta-coefficient=-0.25981, P<.0001, respectively). The Omron device meets AAMI criteria with the exception of diastolic BP in youth ages 13 to 19 years. However, Omron underestimated the prevalence of hypertension and device agreement decreases with increased systolic and diastolic BP.