Electrochemical oxidation of reactive blue 222 (1.6 mM, 1300 mg dm-3 COD) in 0.5 M Na2SO4 aqueous media (which resembles a textile wastewater) on a boron-doped diamond electrode (BDD) was studied, using bulk electrolysis. The influence of current density and hydrodynamics was investigated. The degradation rate depends on current density and with hydrodynamics. Generated carboxylic acids such as ascorbic, oxalic, benzoic, citric, fumaric and maleic were detected and quantified by HPLC measures. The electrolysis with a BDD electrode at 20 mA cm-2 and mean linear flow velocity of 146 cm s-1was the only experiment that led to 100% mineralization of reactive blue 222, with an energy consumption of 11.8 KWh m-3 and fractional integral current efficiency of 0.7.