Landfill leachate is a concern in the wastewater field due to its toxicity, high ammonium and low biodegradable organic matter concentrations. The aim of this paper is to study the reliability of landfill leachate treatment using Sequencing Batch Reactor (SBR) technology for biological nitrogen removal. During the study the SBR pilot plant treated successfully 0.48 kg N x m(-3) d(-1) of urban landfill leachate. Furthermore, high nitrogen removal efficiencies (80%, on average) have been achieved by the operational conditions applied (step-feed strategy and alternating anoxic-aerobic conditions).