OBJECTIVES: Accuracy of blood pressure measuring devices is of prime importance and should be validated before devices are used clinically. We carried out an independent evaluation of the Oscar 2 oscillometric ambulatory blood pressure monitor (SunTech Medical, Model 222) according to the British Hypertension Society (BHS) Protocol. METHODS: Validation of the Oscar 2 was carried out in accordance with Part 1 of the British Hypertension Society protocol. Having successfully completed the first three phases, in the static validation phase blood pressure measurements were made on 114 participants simultaneously by two observers blinded from each other's readings and those of the device, giving 255 data pairs for systolic and diastolic blood pressure. Readings were made using simultaneous same-arm measurement, each observer using a dual-head binaural stethoscope and a calibrated mercury sphygmomanometer. Data were recorded independently, to the nearest 2 mmHg and were checked by the supervisor who operated the device. RESULTS: The device mean and observer means (and standard deviations) were exceptionally close across a high range of pressures, with a mean difference for the better observer of 0±7 mmHg and -1±6 mmHg for systolic and diastolic blood pressure, respectively. With 62% of all systolic blood pressure standard vs. device differences equal or less than 5 mmHg, and 70% of all similar differences for diastolic blood pressure equal to or less than 5 mmHg, the device was categorized as Grade A for systolic and diastolic blood pressure. CONCLUSION: The Oscar 2 was graded A for both systolic and diastolic blood pressure by the British Hypertension Society protocol and can be recommended for clinical use in an adult population.