BACKGROUND: High blood pressure (BP) significantly increases overall cardiovascular risk, the incidence of ischemic heart disease and stroke. One of the most important causes of insufficient BP control is low treatment compliance. Reminders and electronic compliance monitoring have been shown to be effective in improving patient compliance to some extent, but the combined effect has not been documented. OBJECTIVE: To assess the impact of an electronic reminder and monitoring device on patient compliance and BP control. METHODS: All patients received medical treatment with telmisartan once daily and were randomized to either electronic compliance monitoring with a reminder and monitoring device or standard therapy for 6 months. Both groups were crossed over after 6 months. Intervention effectiveness was assessed using self-reported compliance and BP. RESULTS: Data from 398 patients were analysed. In the first half of the study, patients using the device reported 91% compliance versus 85% in the control group. This difference diminished after crossover (88 versus 86%). BP was not affected. Electronic monitoring data on compliance revealed taking, dosing and timing compliance between 45 and 52% in study group 1, and between 32 and 38% in study group 2. CONCLUSION: The Helping Hand reminder device was most suitable if used for newly diagnosed hypertensive patients, when it improved compliance by 6%. With the present medical treatment, the device does not have any influence on BP control, but with less forgiving medications, the device might make a significant difference. The use of the device can be an easy and effective way to improve compliance in selected patients.