Modern power systems are interconnected and exposed to external as well as internal disturbances. The stable operation of power system (Power System Stability) is the subject of great interest for power engineers for the last few decades. Stability in power system is achieved by many means, but nowadays FACTS controllers, which are a family of flexible alternating current transmission system devices, are widely used to enhance stability. Among these is the unified power flow controller (UPFC), the most versatile and prominent that controls the flow of active power and reactive power and also stabilize the voltage at selected bus. This paper presents an approach towards stability using UPFC in multi-machine power system. The proposed work is implemented in MATLAB/SIMULINK. The power system is simulated with and without UPFC to check the performance of the controller under fault condition. The simulation results show that in case when UPFC is used it takes much less time to enhance power stability after fault occurrence compared to the case without using UPFC.