Abstract: A fully automatic, non-invasive, digitally-controlled blood pressure measuring apparatus is described with LED displays for displaying systolic and diastolic blood pressure levels, an inflatable cuff for occluding an artery, a pump for inflating the cuff, a cuff-mounted sensor for detecting Korotkoff sounds, adjustable gain-amplifying apparatus for maintaining linearity of the Korotkoff sound levels over a wide range of human individuals, circuits for automatically determining systolic and diastolic pressure levels and pressure release apparatus for preventing overinflation of the cuff.