Cyclic voltammogram and differential pulse polarograph of octaethyl porphyrin iron(III) chloride in dichloromethane was investigated in the presence of pyridine, imidazole and collidine. Values of E1/2 for FeIII/FeII redox reaction were monitored as a function of axial group concentration, and on the basis of these data, an overall oxidation-reduction and ligand addition scheme was formulated. Addition of pyridine resulted in anodic shift for oxidation wave from –0.16 V to –0.06 V while for imidazole and collidine we observed a cathodic shift.