Abstract: Measurement of blood pressure is one of the most common procedures done in a clinical and an ambulatory environment. It is usually done with a sphygmomanometer, where an inflatable cuff is attached to the arm of a patient and the systolic and diastolic pressures are determined, typically by listening to the Korotkoff sounds. Although this method is over 100 years old and widely used, it is well known that it has severe shortcomings. The present invention covers a novel device and method to continuously measure blood pressure using a noninvasive approach. A surface acoustic wave (SAW) pressure sensor is placed on a flexible substrate and placed on the wrist of a patient. This blood pressure sensing device communicates wirelessly with a monitor that is placed several meters away. The monitor can also be a wristwatch worn by the patient. The invention further encompasses a calibration procedure to convert the relative blood pressure values into absolute values.