Guidelines recommend home blood pressure monitoring (HBPM) to improve blood pressure control, but the attitudes of primary care physicians and their hypertensive patients towards its use are not known. A 28-item self-administered survey about home blood pressure monitoring was mailed to a random sample of 1418 primary care physicians in Ontario and 765 (55%) were returned. Of the 478 physicians treating hypertension, 299 agreed to give surveys to their hypertensive patients. We received 149 patient surveys. The majority of primary care physicians (63%) often or almost always encouraged their hypertensive patients to monitor their own blood pressure at home. Only 13%, however, preferred home blood pressure monitoring to office or ambulatory readings for diagnostic purposes and 19%, to guide therapy. Physicians had concerns about patients becoming preoccupied with home monitoring (70%) and the accuracy of home devices (65%). Most patients (78%) had a device at home, and 84% indicated that their doctor encouraged them to measure blood pressure. Yet, 80% received no advice from their physician on the type of device to purchase, only 8% had specific training on proper measurement technique, 68% did not regularly take the results to the doctor and 39% did nothing specific about alarming readings. Primary care physicians prefer office or ambulatory to home readings to make diagnostic and therapeutic decisions. While home monitoring is popular among patients, its clinical usefulness is undermined by the lack of reliable purchasing information, standard measurement protocols, proper training on measurement technique and specific instructions on handling and interpreting results.