Electrochemical oxidation and reduction of the helaktyn red F5B dye on Ti/TiO2(97%)-RuO2(3%) electrode was studied by voltammetry. The electrooxidation started at the potential of 0.74 V and proceeded in at least one electrode step before the potentials reached the value at which oxygen evolution started. The substrate was also reduced in at least two electrode steps before the potentials reached the value at which hydrogen evolution started. Electroreduction started at the potential of -0.15 V. Both processes were found irreversible. Under conditions of linear diffusion, the kinetic parameters of the dye electrooxidation were determined. Half-wave potential was 0.82 V. Anodic transfer coefficient was 0.45 and heterogeneous rate constant 2.5.10(-4) cm/s.