An overview of permanent magnet synchronous (PMS) motors and the related control system are presented in this chapter as introductory materials for the rest of the book. The interconnections of the control system to the power electronic inverter and the motor are emphasized. In addition, the major parts of the system are overviewed. Pulse width-modulated voltage source inverter, as the most commonly used power converter in PMS motor drives, is briefly discussed. PMS motors configurations and operating principles are also presented after considering characteristics of permanent magnet materials. Major PMS motor control methods including vector control, direct torque control, predictive control, deadbeat control, and combined vector and direct torque control are briefly reviewed. Finally, several rotor position and speed estimation schemes, and offline and online parameter estimation methods are overviewed.