Comparison studies on the codeposition of Al with Co, Cr, Zn or Mn From AlBr3-dimethylethylphenylammonium bromide solutions in toluene containing the acetylacetonate of a corresponding metal were made. They supported the view that the electrode potentials of selected metals are significantly closer to Al in organic medium than in aqueous solutions. However, if the potential difference between Co or Cr and Al approaches by the factor 1.2-1.8 in organic medium, it reduces between Zn and Al almost hundred times, whereas Mn becomes even less noble than Al in contrast to aqueous solutions. Distinct reduction waves were observed only for Co and Zn preceding the Al codeposition. Meanwhile, the priority of Cr deposition can be determined only by analysis of the anodic process. The character of the initial stages of the deposition process is influenced strongly by the metal codepositing with Al, the electrodeposition of Al at Pt involves an instantaneous nucleation process in the case of Co and Mn; and it is progressive nucleation in the case of Zn. (C) 2000 Elsevier Science Ltd. All rights reserved.