A new method for estimation of electrical parameters in Induction Machines (IM) is presented. Evaluation of the parameters is performed by considering the envelope of the stator currents under motor start-up, thus avoiding the high sampling rates necessary for logging the actual currents. The use of start-up data makes the method attractive in the IM control and monitoring applications where the parameter estimates can be used for adjusting the control law or evaluating the motor condition. It is also demonstrated that the use of a simplified decoupled dynamic model of the IM in the estimation algorithm does not significantly worsen the quality of the obtained parameter estimates. Both simulations and experiments show fast convergence of the suggested algorithm.