Abstract Mimosa extract was examined as a corrosion inhibitor for brass-MM55 in 0.5M H2SO4 by using electrochemical impedance spectroscopy and the polarization technique. The polarization studies showed that Mimosa extracts acted as anodic-type inhibitor. The percentage inhibition efficiency (η), was found to increase with increase of the inhibitor concentration due to the adsorption of the inhibitor molecules on the metal surface. In addition it was established the adsorption follows Temkin adsorption isotherm. Moreover some thermodynamic data were calculated and discussed. The results showed that Mimosa extract could play significant role as a corrosion inhibitor for brass-MM55 in 0.5M H2SO4 environment.