Abstract: An instrument for measuring blood pressure by sensing the Korotkoff sounds which prevail only between the systolic and the diastolic points. The instrument used is essentially a hand held device which is held in direct contact with the skin over an artery. The instrument has a pressure-sensitive element which responds to pressure, and a crystal transducer which responds to Korotkoff sounds. A pressure is exerted on the instrument occluding the artery and stopping the Korotkoff sounds, and, as the pressure is reduced and the Korotkoff sounds commence, the crystal transducer senses the vibrations from the artery which vibrations are Korotkoff sounds. The crystal triggers a memory circuit, the contents of which are shown on the digital display. The digital display shows the pressure sensed by the strain gauge at the time the sounds appear at the systolic point and again at the diastolic point.