BACKGROUND: Automatic noninvasive blood pressure measuring devices should be independently validated prior to marketing by using standard guidelines such as those published by the Association for the Advancement of Medical Instrumentation and British Hypertension Society. OBJECTIVE: To assess a new noninvasive oscillometric automatic home blood pressure (Omron HEM-737 IntelliSense; Omron Healthcare Inc., Vernon Hills, Illinois, USA). METHODS: We compared the device's measurements with mercury column measurements for 90 subjects (270 measurements). In addition to calculation of the limits of agreement for the device versus observers, we also dtermined the impacts of age, level of blood pressure, body mass, and arm size on the levels of agreement. RESULTS: Observers showed that close agreement was attained, with mean differences of 0.42 +/- 3.65 mmHg for systolic blood pressure and 0.37 +/- 3.59 mmHg for diastolic blood pressure. The proportions of values agreeing to within 5, 10, and 15 mmHg were 88, 99, and 100% for systolic and 86, 100, and 100% for diastolic blood pressure for the two obsevers. The observer-device disagreement was 0.76 +/- 6.55 mmHg for systolic and 1.0 +/- 5.5 mmHg for diastolic blood pressure. The proportions of values agreeing to within 5, 10, and 15 mmHg were 71, 93, and 97% for systolic and 77, 96, and 98% for diastolic blood pressure for the observers and device. CONCLUSIONS: The Omron HEM-737 IntelliSense satisfied the Association for the Advancement of Medical Instrumentation's criteria for a general adult population across large ranges of age, blood pressure, body mass, and arm circumference. These findings support the use of this recorder for out-of-office self-monitoring of blood pressure.