The influence of Cyclohexyl thiourea (CHTU) on corrosion and hydrogen permeation through mild steel in 1N H2SO4 and 1N HCl has been studied using weight loss measurements and various electrochemical techniques. The compound is found to be more inhibitive in H2SO4 than in HCl. Potentiodynamic polarization studies clearly indicate that CHU behaves as a cathodic inhibitor. Hydrogen permeation studies and AC impedance measurements also prove an improved performance of the compound in H2SO4. The adsorption of this compound on the mild steel surface obeys Temkin's adsorption isotherm.