Kinetics of electrocatalytic oxidation of arsenite ions has been investigated at a Pt disk electrode using cyclic voltammetry, convolution potential sweep voltammetry and electrochemical impedance spectroscopy. A complimentary environment pertaining to oxidation reactions of arsenite ions is attained in the acidic medium compared to a neutral or basic medium. It is suggested that in the neutral and basic media, direct electron transfer from the solution to electrode instigate the oxidation process without any pre adsorption. Meanwhile, in the acidic medium, prior to oxidation, arsenite ions are adsorbed on the Pt surface and a stepwise reaction mechanism is involved. Using impedance analysis, it is suggested that different forms of surface oxides at various pH values control the oxidation kinetics. (C) 2016 Elsevier Ltd. All rights reserved.