Abstract D. C. polarographic and cyclic voltammetric studies on the reduction of iron(II) complexes with bidentate imine ligands: 1,10-phenanthroline, 4,7-dimethyl 1,10-phenanthroline and 4,7-diphenyl-1,10-phenanthroline, have been carried out in acetonitrile solutions with 0,8 M tetraethyl ammonium perchlorate as supporting electrolyte. The iron(II) complexes gave a five-step reduction wave. The behavior of the first three steps was found to be diffusion controlled and these steps were to be considered as successive reduction of the iron(II) in the complex. The other steps were to be ascribed to the reduction of the ligand. All three complexes led to the formation of the species Fe(L) 3 − (where L is the ligand). The effect of substituent upon the reduction mechanism was also discussed.