A temperature compensator for a pressure gauge or the like, including a body having a first and second cylindrical cavity coaxial of each other and communicating with each other, a sensing port communicating with one end of the first cylindrical cavity, a vent port communicating with the other end of the first cylindrical cavity, and a compensating port communicating with the second cylindrical cavity, a sense responsive piston positioned in the first cavity intermediate the sensing and vent ports, a compensating piston positioned in the second cavity, the sense responsive and compensating pistons being affixed to each other for simultaneous axial movement, resilient means urging the sense responsive piston towards the sensing port and thereby the compensating piston towards the compensating port, and a closed temperature sensing vessel having communication with the sensing port.