The corrosion inhibition efficiency of 3-(4-chlorobenzoylmethyl) benzimidazoliumbromide in water medium has been evaluated using electrochemical and other techniques. The mixed type inhibitive behavior of the inhibitor was evaluated by potentiodynamic polarization study. The inhibition efficiency increased with increasing pH up to 7.0 and showed a decrease with rise in temperature of the medium. Charge transfer resistance (Rct) values confirmed the formation of a protective layer by the adsorption of the inhibitor on the carbon steel surface. The adsorption degree of 3-(4-chlorobenzoylmethyl) benzimidazoliumbromide on the metal substrate obeyed Langmuir adsorption isotherms. Surface characterization of the carbon steel in the absence and presence of inhibitor has been monitored by atomic force (AFM) and scanning electron microscopy (SEM) with energy dispersive X-Ray spectroscopy (EDX). Quantum chemical analysis (QCA) data supported the adsorption efficiency of the inhibitor. The results obtained from electrochemical noise analysis (ENA) were in good agreement with other studies.