In this paper, the load frequency control of a two-area system comprising a Thermal Power Plant and a Hydro-Electric Power Plant is discussed. In the two-area system, the thermal power plant and the hydroelectric power plant have a tie line between them. The excess demand in an area is supplied by the power plant in the other area via the tie line. The frequency deviation of the supply due to balancing must be avoided irrespective of the load demand. Thus, a suitable control system must be developed to control the flow rate of the working fluid in the respective plants such that the frequency deviation is minimized proactively with a quick response. The paper describes the integration of secondary-level control i.e. integral gain control to the primary-level governor control in the power plants under study to nullify the steady-state frequency deviation of output supply. Further, the incorporation of fuzzy logic into the secondary-level control reduces the time involved in attaining the required frequency for constantly varying unprecise inputs. The two-area system is modelled and simulated using MATLAB Simulink and conclusions are derived from the results comparison of the system with the Integral controller and with the fuzzy logic controller.