Corrosion behavior of mild steel in 1M Sulphuric acid with an anti-bacterial agent, viz., Clonazepam [CPZ] as corrosion inhibitor has been studied by using mass loss, potentiodynamic polarization, electrochemical impedance spectroscopy and hydrogen permeation studies. All these techniques reveal that inhibition efficiency increases with the increase in the concentration of antibacterial agent. Polarization studies indicated that inhibitor acted as cathodic inhibitor. It was found that the adsorption of green inhibitor on the mild steel surface obeying Langmuir adsorption isotherm. © 2016 University of Manchester and the authors.