In this study, the effects of various operating conditions such as treatment time, DC current, initial pH, initial H(2)O(2) concentration and distance between the electrodes on treatability of landfill leachate by using electro-Fenton (EF) method were examined. The settling characteristics of waste sludge produced from the treatment were also determined. According to the results, EF method can be used efficiently for the treatment of landfill leachate by using the proper operating conditions. The best removal efficiencies were obtained when: treatment duration is 20 min, constant DC current value is 3A, H(2)O(2) concentration is 2000 mg L(-1) and the initial pH value is 3. For these conditions, 72% COD, 90% color, 87% PO(4)-P and 28% NH(4)-N removals were obtained. It was also observed that using electrode distance between 1.8 cm and 2.8 cm increases efficiency of the COD removal, significantly. Sedimentation characteristics of the waste sludge produced from the EF method is fairly good. (C) 2008 Elsevier B.V. All rights reserved.