The inhibition of corrosion of reinforcing steel in simulated concrete pore solution (SCPS) has been studied using mass loss, gasometric measurements, potentiodynamic polarization and impedance studies using Mezlocillin (MZN) as a green inhibitor. The studies clearly revealed that MZN acted as cathodic inhibitor. Diffused reflectance spectra confirmed the formation of adsorbed film of inhibitor on reinforcing steel in SCPS. © 2015, Sphinx Knowledge House. All rights reserved.