An assistance method for adjusting the pressure of a tire mounted on a wheel of a motor vehicle having an electronic module adapted to transmit, to an on-board central unit in the vehicle, signals including data representing the pressure of the associated tire, this assistance method includes, in the first place, during an action of adjusting the pressure of a tire, determining, after receiving a number n of initial measurement signals, where n≧2, the gradient or slope Cd of the straight line representing the variation of the measured value Pm(t) of the pressure as a function of time. Next, on receiving each subsequent measurement signal, the remaining time required to obtain the setpoint pressure Pc is deduced from the ratio |Pc-Pm(t)|/Cd, and, on the expiry of this remaining time, initiating a procedure for managing the cessation of the pressure adjustment, and signaling the end of the adjustment.