Four n-alkyl amines (6, 8, 10 and 12 carbon atoms) were investigated as corrosion inhibitors for mild steel in 2 M hydrochloric acid solution using gravimetric and polarization techniques. The influences of temperature (278-308 K) and inhibitor concentration (10(-1)-10(-6) M) were studied. Protection efficiency improved when the inhibitor concentration and the length of the alkyl chain were increased. The four amines tested were adsorbed on the mild steel surface according to a Frumkin isotherm.