The electrochemical oxidation of 2,4,6- trinitrophenol (TNP) has been studied on boron-doped diamond electrodes on acid medium by cyclic voltammetry and bulk electrolysis. The results showed that in the potential region where the supporting electrolyte is stable, reactions occur, resulting in the loss of activity due to electrode fouling. Galvanostatic electrolyses cause complex oxidation reactions that lead to incineration of TNP. Phenol, benzoquinone, maleic, and oxalic acid have been detected as soluble products during the electrolysis of TNP. These results suggest that the electro-oxidation of TNP begin by the release of nitro groups from the aromatic ring to form non-nitrogenated phenolic compounds. These compounds are transformed into carboxylic acids which end to be oxidized to CO2. The complete removal of organic compounds contained in the waste has been obtained in sulfuric medium. © 2005 The Electrochemical Society. All rights reserved.