Corrosion inhibition effect of S-Benzylthiuronium chloride (SBTC) on steel in 1.0 M HCl and 0.5 M H2SO4 is presented here. Effect of its concentration on protection efficiency was studied by techniques like weight loss, polarization and electrochemical impedance spectroscopy and the effect of temperature by weight loss method. Results indicated that SBTC is more competent in HCl and its protection efficiency increase with its concentration and decreased with temperature. Adsorption study revealed the physical adsorption of SBTC molecules on steel surface. Results were justified by scanning electron micrographs.