The Citrus aurantifolia leaves extract was tested for corrosion inhibition on the mild steel in a 0.5M sulfuric acid solution using weight loss, Tafel and EIS. The state of mixed adsorption with the potentiodynamic polarization effect is shown. Citrus aurantifolia showed the strongest corrosion inhibition of 96.46% at a concentration of 250mg/L. SEM and AFM are used to verify the formation of a protective layer on the surface of mild steel. The adsorption phenomenon was verified using UV-Vis. spectroscopic technique, whereas FT-IR confirmed the presence of several functional groups containing heteroatoms. Adsorption of the inhibitory molecules on the mild steel surface followed the Langmuir adsorption isotherm. All obtained results ensure that C. aurantifolia leaves extract can form an effective blocking layer and control the corrosion process.