Electrochemical degradation of 2,5-dichloro-1,4-phenylenediamine (DP) in aqueous solution by anodic oxidation was investigated. Linear sweep voltammograms and cyclic voltammograms were studied. The influence of operating parameters on electrochemical oxidation of DP was studied as a function of the current density, initial pH, and initial concentration of DP. The degradation kinetics analysis indicated that the electrochemical degradation of DP followed a first-order reaction. The degradation intermediates during electrochemical oxidation were analyzed by UV–vis spectrophotometer, ionic chromatograph (IC), and gas chromatography/mass spectrometry (GC/MS). The combustion efficiency of DP at the anode was also estimated. The electrochemical oxidation of DP resulted in the release of NH4+ and Cl−. Based on these results, a degradation mechanism for electrochemical degradation of DP by anodic oxidation was proposed.