Economic losses due to corrosion are direct, as well as, indirect and affect the economy of country. Corrosion inhibitors are one of the widely used methods to control corrosion. Particular advantage of corrosion inhibitor is that often can be implemented or changed in situation without disturbing a process. Due to toxic nature and high cost of some inhibitors currently in use it is nearly to develop environmentally acceptable and less expensive inhibitors. Natural product can be considered as a good source for this purpose. As evaluation of the performance of acid extract of Ficus benghalensis (FB) bark on the corrosion inhibition of MS in 2N, 3N and 4N hydrochloric acid at different temperatures were studied. Weight loss, electrochemical polarization and impedance measurement techniques were conducted. The efficiency of the inhibitor was noticed to increase with increase in concentration of the inhibitor.