Abstract A high-sensitivity, surface-micromachined piezoresistive pressure sensor is proposed for size-demanding applications. The sensor design and theoretical analysis is presented. The sensor combines monocrystalline silicon piezoresistors and a polysilicon membrane. The sensor is fabricated using surface-micromachined technology, with an SOI wafer as the starting material. Two variations of the sensor are fabricated, tested, and characterized. The measured sensitivity is approximately 24mV(Vatm)−1, which is similar to that of traditional pressure sensors. The influence of design and technology factors on the sensor performance is discussed.