Objectives: The use of home blood pressure measurement in the follow-up of antihypertensive treatment is rapidly increasing. Published non-commercial comparisons or validation studies between different types of home monitors have been rare. We describe here the results from a study in which three home blood pressure monitors from two manufacturers were compared.Methods: Three different upper arm automatic blood pressure measuring devices: Microlife BP 3AC 1-1, Microlife BP3AG1 and Omron M4-I were compared in a randomized study. It was carried out among 65 Finnish normo-and hypertensive people who used all three devices at home for one-week of blood pressure monitoring and measured their blood pressure twice both in the morning and in the evening.Results: An about 2 mm Hg difference in systolic, diastolic and mean pressure was observed between Omron M4-I and the Microlife devices whereas the Microlife devices showed equal performance. A significant correlation in the mean pressure was observed between all three devices. Conclusions:Although all these devices have passed the British Hypertension Society (BHS) qualification, the blood pressure monitoring results in this study showed that there may be a small blood pressure difference between the devices from separate manufacturers. Blood pressure monitoring results are most reliable when the same device is used consistently.