The invention concerns a method for adjusting motor parameters in a variable speed drive intended to control an electric induction motor M. The method includes a step for determining differences .DELTA.I.sub.D and .DELTA.I.sub.Q between motor flux current and motor torque current references and measurements, a step for calculating a correction value .DELTA.R.sub.R of the rotor resistance and a correction value .DELTA.L.sub.R of the rotor inductance from the integral terms of the differences .DELTA.I.sub.D and .DELTA.I.sub.Q, a step for adjusting values of parameters of the motor model based on .DELTA.L.sub.R and .DELTA.R.sub.R, a step for generating control voltages U.sub.D and U.sub.Q to be applied to the motor M using said adjusted motor parameter values.