This paper deals with the speed control of induction motors applying a fractional order proportional-integral (FOPI) controller within a field oriented control (FOC) scheme. The FOPI controller has a similar structure to the classic proportional-integral (PI) controller but FOPI controller considers non integer integration orders in determining the control action. This allows obtaining responses of the controlled system with different characteristics such as oscillations, stability and rise time. In this study FOPI strategy is simulated within a FOC scheme using a mathematical model of an induction motor. © 2010 IEEE.