Electrochemical studies (cyclic voltammetry, voltammetry at rotating disc electrode and coulometry) have been carried out in acetonitrile, at a platinum electrode, for three Co(III) containing cobaloximes having the same in plane ligand (the butanedione dioximate or dimethylglyoximate Hdmg(-)). The complexes examined, [Co(Hdmg)(2)I(py)], H[Co(Hdmg)(2)I-2] and [Co(Hdmg)(2)(py)(2)]NO3 (where py=pyridine), are neutral, anionic and cationic, respectively. Their voltammetric traces reveal the presence of a series of oxidation and reduction charge transfer processes. The combined use of mixed axial ligand and appropriate chemical reactions, enables the accumulation of information on the nature (cobalt based, iodide based or glyoximate-centered) of the electron transfer processes that occur during the reductive and the oxidative processes. Some solvolysis of the complexes is observed and discussed in terms of axial ligand exchange equilibria. The uv-visible spectra for these complexes in acetonitrile show some absorptions at low energy which are attributed either to pi-pi* transition, metal-to-ligand charge transfer or to d-d transitions.