This paper analyzes various methods of capacitor placement in a radial distribution system considering the optimal power flow. It compares the total system losses with conventional power flow to optimal power flow in all the methods such as Index vector method (IV), voltage sensitivity index method (VSI), combined power loss sensitivity method (CPLS), voltage stability index method (VStI) and voltage stability margin (VSM) method. IEEE 33 bus radial distribution system (RDS) is considered and optimal power flow is performed using GAMS for the above analysis.