This paper deals with a novel approach of artificial intelligence (AI) technique called Hybrid Neuro-Fuzzy (HNF) approach for Load Frequency Control (LFC) of four area hydrothermal interconnected power system. The advantage of this controller is that it can handle the non-linearities at the same time it is faster than other conventional controllers. The effectiveness of proposed controller in increasing the damping of local and inter area modes of oscillation is demonstrated in four area interconnected power system. Area-1 and area-2 consists of thermal reheat power plant whereas area-3 and area-4 consists of hydro power plant. Performance evaluation is carried out by using ANFIS and conventional PI control approaches. The performances of the controllers are simulated using MATLAB/SIMULINK package. The result shows that intelligent controller is having improved dynamic response and at the same time faster than conventional controller.