It has recently been synthesized a Schiff base (E)-2-hydroxy-5-(2-benzylidene) aminobenzoic acid and characterized by FTIR, UV-vis and H-1 NMR analysis. The electrochemical behaviour of mild steel in 1.0 M HCl solutions in the absence and presence of Hha has been investigated by electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy. The inhibition efficiency was found to increase with rise in concentration of synthesized molecule. Scanning electron microscopy observations of mild steel surface confirmed the existence of such an adsorbed film. Contact angle on the metal surface was also measured. Computational analyses of (E)2-hydroxy-5-((2-hydroxybenzylidene) amino benzoic acid were done at B3LYP/6-31G(d) level in gas phase. Sensitivity of this compound towards Fe2+ and Fe3+ ions were determined. Interaction mechanism was proposed.