One of the most important steps in solid waste management is the selection of an appropriate landfill site. The site selection process requires the evaluation and analysis of several criteria. However, the traditional evaluation method is not sufficient for the site selection process. Geographical information system (GIS) technologies are effectively used in the process of site selection, which is a spatial problem. This article describes a raster GIS-based landfill site selection (LSS) method. This method utilizes a raster-based spatial database in which the factors affect the landfill site selection. The final product in this method is the cost surface map showing pixel-based values of the appropriate areas. Furthermore, this GIS-based LSS method was applied for the evaluation of two landfill sites in Trabzon Province in Turkey, for which the traditional evaluation method for site selection was used. The suitability values on the cost surface map of these two landfills have shown that these sites are not appropriate for a solid waste landfill. In conclusion, it was demonstrated that the method of raster GIS-based site selection gives more effective results than traditional methods.