This study presents a fuzzy logic based control technique to regulate the power and enthalpy outputs in a boiler of a 765 MW coal fired thermal power plant. An approximate mathematical model of the thermal power plant was developed by using real time data on Computer Aided Design and Control (CADACS) software. Conventional proportional, integral and derivative (PID), fuzzy logic (FL) and fuzzy gain scheduled proportional and integral (FGPI) controllers have been applied to the power plant model. The simulation results show that the FGPI controller developed in this study performs better than the rest of the controllers on the settling time and overshoot of power and enthalpy outputs. (c) 2005 Elsevier Ltd. All rights reserved.