This paper deals with artificial neural network (ANN) based ANFIS approach for automatic generation control (AGC) of a multi-area hydro-thermal system. The proposed ANFIS controller combines the advantages of fuzzy controller and quick response and adaptability nature of ANN. Appropriate generation rate constraints (GRC) have been considered for the thermal and hydro plants. The hydro area is considered with an electric governor and thermal area is considered with reheat turbine. The design objective is to improve the frequency deviations of the interconnected system. 1% step load perturbation has been considered occurring either in any individual area or occurring simultaneously in all the areas. Simulation results are presented to show the improved performance of ANFIS controller in comparison with an optimized conventional integral controller.