A monolithic pressure transducer using polycrystalline silicon for both the diaphragm material and an integral piezoresistor has been fabricated. The device can be made with good repeatability and with easily varied diaphragm thickness. Electrical-output linearity is very good over a pressure range of 0–11 cm Hg for a 2.4 μm diaphragm having an area of 0.00136 cm2.