Abstract: In order to provide a technique for determining high-quality blood pressure values of a patient, especially in cases of unsupervised blood pressure measurements in a home environment, it is suggested to use a system (1) for determining the blood pressure of a patient (2) comprising a blood pressure measuring device (3, 4) for measuring a blood pressure value, an auxiliary device (6, 7, 8, 9) for measuring the motor activity of the patient (2) during a defined period of time prior to the blood pressure measurement, and a processing device (13, 14), said processing device (13, 14) being adapted to obtain the motor activity information and the blood pressure value, said processing device (13, 14) being further adapted to automatically assess the blood pressure value using the motor activity information, and said processing device (13, 14) being further adapted to provide a measuring result depending on the result of the assessment.