The paper investigates the application of a fuzzy logic – based governor controller as a technique of artificial intelligence techniques for stability enhancement of a multimachine power system. A fuzzy controller is designed to operate in real time to improve each generating unit transients in a multimachine system through the governor loop. The fuzzy controller requires two inputs signals, speed deviation and acceleration of the machine and generates one output as a supplementary signal into the governor loop when the excitation system is fixed. The developed fuzzy controller, whose control signals are adjusted using on line measurements, offers better damping effects for generator oscillations under large disturbances compared to turbine speed governor with conventional controller. Computer simulations of a 3 unit power system show that employing this type of control is effective in reducing excessive over and under frequency deviations.