The effect of some ol-amino acids on the inhibition of pitting corrosion of Al in 0.1 M NaCl solution was studied by the potentiodynamic technique. All inhibitors used shift the pitting potential (E-p) and the protection potential (E-pp) towards more noble values. The order of effectiveness of the inhibitors was arginine > histidine > glutamine > asparagine > alanine > glycine. The adsorption of amino acids on platinum was investigated by cyclic voltammetry using a flow cell technique. The results confirm that the inhibition efficiency of the amino acids studied is due to their adsorption on the metal surface. Variation in inhibition efficiency with the structure of the compounds was interpreted in terms of the number of adsorption active centres in the molecule, the molecular size and the mode of adsorption.