Abstract: This study deals with the Nonlinear Control (NLC) applied to the speed regulation of Permanent Magnet Synchronous Motor (PMSM). The control problem of a PMSM is solved by the application of a nonlinear input-output linearization technique. A state feedback input-output linearizing control is designed for a third order model of a PMSM which included both electrical and mechanical dynamics. Speed and torque control of permanent magnet synchronous motors are usually attained by the application of position and speed sensors. However, speed and position sensors require the additional mounting space, reduce the reliability in harsh environments and increase the cost of motor. Many studies have been performed for the elimination of speed and position sensors. Our proposed control strategy is based on an accurate Extended Kalman Filter (EKF) which estimates speed, position, load and rotor-fixed current id, iq. The investigations show that the EKF is capable of tracking the actual rotor speed and position provided that the elements of the covariance matrices are properly selected. Moreover, the performance of the EKF is satisfactory even in the presence of noise or when there are variations in permanent magnet synchronous motor load.