In this study, experimental results of the reactive power compensation of a system using a fuzzy logic controlled synchronous motor have been presented in detail. The excitation current of the synchronous motor is controlled by a PIC 16F877. Measured currents, voltages and power factor of the system are used as input variables for the PIC 1617877 controller. Experimental results show that the developed system is more sensible, reliable and economical than other systems with capacitors, since the synchronous motor may also be used in the system for any other purposes. (C) 2003 Elsevier Ltd. All rights reserved.