An aqueous extract of Pithecellobium dulce has been studied as a corrosion inhibitor in controlling corrosion of mild steel in 1 N HCl medium by weight loss, electrochemical impedance spectroscopy and potentiodynamic polarization techniques. Polarization study revealed that the inhibitor acts as mixed type of inhibitor. The electrochemical impedance study further confirms the formation of an adsorbed film on the mild steel. The adsorbed film over the mild steel surface has been confirmed by Scanning Electron Microscope (SEM) analysis. The adsorption character of plants extract on mild steel surface obey Temkin isotherm.