Pyridine and its selected derivatives (symmetric collidine and 2,5-dibrompyridine) have been studied as corrosion inhibitors for high purity aluminium in a 2m NaCl solution at 25 degrees C and 35 degrees C using d.c. polarization techniques. The investigations were carried out with a wide range of concentrations of the compounds examined (from 0.5 x 10(-5) M to 1 x 10(-3) M). The results show that the derivatives are adsorbed on aluminium according to the Freundlich isotherm. The values of the standard free energy of adsorption suggest that the adsorptive properties of the compounds under consideration approach the physical type. The polarization curves show that the compounds act as cathodic-type inhibitors.