Abstract: A microdischarge-based pressure sensor that includes an anode, two cathodes, a drive circuit connected to the electrodes, and a measurement circuit that permits sensing of transient current pulses flowing through at least one of the electrodes. One of the cathodes is interposed between the anode and other cathode, and it includes a central opening which permits a microdischarge to occur between the anode and each cathode in response to applied voltage pulses from the drive circuit. Changes in relative current between the two cathodes are indicative of changes in ambient pressure in the microdischarge chamber. In other embodiments, a sealed chamber can be used with one of the electrodes acting as a diaphragm which deflects based on external pressure and changes its inter-electrode spacing, thereby altering the relative cathode currents.