Accumulation of leachate at municipal solid waste (MSW) landfills is a significant environmental problem. The analysis of known technologies of leachate treatment was performed. It was established that it is not effective to use the same technology to treat leachate in two different periods: before the landfill closure and reclamation process as well as afterwards. The application of integrated two-stage aerobic-reagent pre-treatment technology with subsequent full treatment at municipal wastewater treatment plants was proposed for these purposes. The results of laboratory studies of optimal parameters of technology realization for the pre-treatment of Lviv MSW landfill leachate were presented. Recommendations for the practical implementation of the combined two-stage aerobic-reagent technology for the landfill leachate pre-treatment were developed.