A device for measuring the pressure of tires, particularly for aircraft, comprising a passive sensor adapted linearly to convert a variation in pressure into an electrical information variation, in situ, means adapted to convey the electrical information from the sensor to the cockpit of said aircraft, a self-oscillator whose oscillation frequency is controlled by the value of said electrical information from the sensor and means adapted to convert the signal issuing from said self-oscillator into a D.C. voltage proportional to a frequency variation, said frequency variation being proportional to said variation in pressure, characterized in that the electrical information from the sensor, before transmission into the cockpit, is applied to the terminals of the primary winding of a high frequency transformer, said primary winding being mechanically fast with the wheel, the secondary winding of said transformer being concentric with respect to the primary winding and mechanically fast with the stationary part of the landing gear, the ratio n of transformation between the primary winding and the secondary winding modifying the electrical information from the sensor according to the square of said ratio n.