The aim of this study is the treatment of Chlorothiazide in an aqueous medium by Electro-Fenton process using a Platinum anode. This pharmaceutical product is used to treat hypertension. Removal rates and mineralization efficiency have been analyzed under different operational conditions. Degradation kinetics well fitted to a pseudo–first–order reaction. Apparent rate constant of the oxidation of Chlorothiazide by electrochemically generated hydroxyl radicals was determined to be 9.49 x 10-2 min-1 at a temperature of 25°C. Chlorothiazide mineralization in an aqueous solution was followed by the analysis of chemical oxygen demand (COD), the degree of mineralization of 93% was achieved after 7 hours of electrolysis.