The retardation of dissolution of Al-SiC composites in 1N HCl could be studied by using sulfaguanidine drug (SGD) as a green corrosion inhibitor. The performance of the compound has been explored using mass loss studies, gasometric measurements, potentiodynamic polarization and impedance analysis. These studies evidently pointed out that the compound performed as cathodic inhibitor in 1N HCl. The adsorption of the drug molecule on Al-SiC surface followed Temkin's adsorption isotherm. The quantum mechanical calculations validated the inhibition efficiency of the compound studied by electrochemical methods. © 2013 University of Manchester and the authors.