Landfill areas have always been a common application for municipal solid waste management. However, land use problems, environmental pollution and increasing recycling implements have limited the amount of solid waste which is stored in the landfill areas. Despite all disadvantages, it is still considered a preferred disposal method fort he solid waste, especially when methane gas released from the areas is used to obtain electrical energy. In this context, the aim of this study is to estimate the landfill gas amounts originating from the Erzurum Solid Waste Landfill area using the LandGEM 3.02 version developed by EPA and to compare it with the methane gas concentrations measured on-site for the last three years. Total landfill gas, methane, carbon dioxide, and NMOC amounts were estimated with the model by choosing the basic parameters of the LandGEM (k and Lo values) according to the Clean Air Act and AP-42 inventory suggested by the EPA. The amount of the same gases was also predicted by manually calculated the k and Lo values (User Specified) with the specific data of the field. Finally, the amount of landfill gases obtained by using all three inventories (the Clean Air Act, AP-42 and User Specified) was compared with the methane concentrations measured in the field in order to confirm the model results. First result is that the methane gas concentrations predicted by the model were nearly close to the real methane measurements on site. Secondly, the operating period determined as 20 years for Erzurum landfill area when it was put into operation in 2008, while it was estimated as 23 years according to the LandGEM model results. Erzurum Solid Waste Landfill area has already been designed for power generation and the energy is produced at present. Therefore, the model can easily be used and verified for future improvement of the landfill area and the prediction of the amount of the energy obtained from the wastes.