This research investigated the effectiveness of electrochemical treatment in treating semi-aerobic landfill leachate. The electrolytic reactor assembly included a pair of aluminium electrodes, a power supply and NaCl as electrolyte. The interactive effects of initial COD, current density and reaction time on treated leachate quality were studied. Regression equations were developed using design-expert software and results were analysed using response surface methodology. At optimum conditions (2000 mg/L initial COD, about 17 mA/cm2 current density, 4 h reaction time and 1 g/l NaCl), SCOD removal, BOD removal and colour removal were estimated to be 82.2, 81.5 and 95, respectively. Copyright © 2010 Inderscience Enterprises Ltd.