This paper work presents a method to receive in a sensorless way the rotor speed and the rotor flux of an induction machine by using a Kalman observer. There is presented the Kalman filter general theory and its applying way for the implementation of an optimal recursive observer, named Extended Kalman Filter (EKF). The observer with EKF for the rotor speed and flux estimation is simulated by using MATLABSIMULINK files, and the conclusions of the simulation study are presented.