The appropriate site selection for municipal wastes disposal is one of the major problems regarding wastes management activities. An inappropriate landfill site may cause negative environmental, economic and ecological impacts. Therefore, the site selection should be carried out carefully considering regulations and constraints both. This study attempts to determine the sites appropriate to establish landfill to dispose municipal solid wastes in Sanandaj city _western Iran_ through combination of Inversion Hierarchical Weight Process (IHWP) and Geographic Information System (GIS). For this purpose, 13 information layers were weighted according to IHWP method. The exclusion of unsuitable area was done using 12 exclusionary criteria which were used to prepare the restriction map. Next, the map from IHWP method was multiplied by the restriction map obtained and the result was classified to determine the suitable area for landfill site selection. Classification of the final map indicated that classes of unsuitable, moderately suitable and most suitable for landfill site selection purpose were 52.0, 17.5 and 3.5 percent of the study area, respectively.