The electrochemistry of six-coordinated cobalt(III) cobaloximatic salts is reported in acetonitrile containing 0.1 M tetrabutylammonium hexafluorophosphate as supporting electrolyte. The investigated compounds are represented as R[Co(GH)(2)I-2] where GH(-) is ethanedial dioximate or glyoximate and R = H+, NH4+, Et(4)N(+), Hqn(+) (quinoleinium). Each complex undergoes up to three oxidative processes and two metal-centered reduction steps within the potential range of the solvent. Except for Et(4)N[Co(GH)(2)I-2], all the other complexes display an additional redox system situated between the two metal centered processes. The more likely origin for this additional redox signal is the reduction of the proton contained in the cations H+, NH4+ and Hqn(+) associated to [Co(GH)(2)I2](-) in the corresponding complexes. The electrochemical behaviour of the cobaloximatic ion is only slightly influenced by the counter cation. The electronic spectra of these compounds show three bands similar to those generally found for cobaloximes.