An automatic blood pressure recording apparatus which eliminates or minimizes substantially all known sources of human error in sphygmomanometry. A uni-directional micorphone maximally sensitive to Korotkoff sounds is contained within the cuff donned by the subject. Analog signals from the microphone are amplified, and digitalized by an electronic circuit whose digital output pulses occur in synchronism with the Korotkoff sounds. Each output pulse actuates a printing stylus which produces a mark on a stationary record chart resulting in a series of marks. The stylus position is controlled by cuff pressure. Thus, the positions of the first and last marks indicate systolic and diastolic pressures.