Titanium dioxide nanoparticles have been used to control corrosion of mild steel in well water in the absence and presence of an aqueous May flower extract. As the concentration of TiO 2 increases, the inhibition efficiency also increases. 100 ppm of TiO 2 offers 84 % inhibition efficiency. The addition of 10mlof May flower extract enhances the inhibition efficiency to 95 %. Adsorption of TiO 2 on the metal surface follows Langmuir adsorption isotherm. Polarization study reveals that the flower extract-TiO 2 system functions as mixed type of inhibitor, controlling both anodic and cathodic reactions. AC impedance spectra reveal the formation of a protective film on the metal surface. This technology may find application in cooling water systems and concrete technology.