The inhibitory activity of some substituted N-arylpyrroles on aluminium corrosion in hydrochloric acid was studied in relation to inhibitor concentration, using potentiodynamic and impedance spectroscopy techniques. All investigated compounds were found to act as cathodic-type inhibitors and inhibition was ascribed to the adsorption of inhibitor onto the electrode surface. The inhibiting efficiency of the additives depended on the inductive power of the groups attached to the benzene and/or pyrrole ring. The carbaldehyde group showed better inhibiting power due to additional condensation on the electrode surface. The impedance results analysed in terms of the polarization resistance showed that the EIS technique can be successfully applied in the determination of corrosion resistance in systems where the corrosion kinetics are not simple.