The leaf extracts of Chromolaena odorata L. (LECO) has been studied as a possible source of green inhibitor for corrosion of aluminium in 2 M HCl using gasometric and thermometric techniques at 30 and 60 A degrees C. Results obtained showed that the LECO functioned as an excellent corrosion inhibitor for aluminium in the acidic environment. Inhibition efficiency increased with extract concentration but decreased with temperature. The adsorption of LECO on Al surface is in accord with Langmuir adsorption isotherm. Both kinetic and thermodynamic parameters governing the adsorption process were calculated and discussed. From the experimental results obtained, it can be concluded that LECO which are biodegradable, environmentally benign, and are obtained from a renewable resource with minimal health and safety concerns have the potential to be a cost effective alternative to synthetic corrosion inhibitors. This present study provides new information on the inhibiting characteristics of LECO extract under specified conditions. The environmentally friendly inhibitor could find possible applications in metal surface anodizing and surface coating in industries.