The inhibition effect of N-benzyl-N'-phenyl thiourea (BPTU) on the corrosion of mild steel in 0.01 and 0.05 N HCl medium has been investigated by potentiostatic polarization technique. Results obtained reveal that BPTU is an efficient anodic inhibitor with greater than 94% of efficiency in the range of temperature studied. The adsorption of inhibitor on the mild steel surface obeys the Temkins' adsorption isotherm and the inhibition is governed by chemisorption mechanism. The kinetic parameters of adsorption obtained reveal spontaneous adsorption and a strong interaction of the compound on the mild steel surface. The influences of the parameters like temperature, HCl concentration and inhibitor concentration on the corrosion of mild steel has also been investigated.