Electrochemical measurements (EIS and PDP) were used to evaluate the anti-corrosive behaviour of SAE on Al in 0.25 M NaOH solutions. The results showed that the inhibition efficiency increases with increasing SAE concentration. PDP measurements revealed that SAE acts as a mixed type inhibitor against the corrosion of Al in the studied solution. EIS measurements indicated the formation of a compact adsorbed layer by inhibitor species on Al surface. Different adsorption isotherm models were tested and paramount fitting was obtained by Langmuir isotherm model. The analysis of FTIR spectra confirmed the formation of a strong bond between inhibitor species and Al surface.