The selection of a tourism development site involves a complex array of decision criteria that may have interdependence relationships within and between them. This study assessed the possibility of establishing natural tourism development site in Lavasan-e Kuchak Rural District (Tehran province) in Iran by using analytic network process (ANP) in a geographical information system (GIS) environment. ANP and the overlaying process were done on GIS. Using 10 information layers in three main criteria including Site Feature, Infrastructures & Services, and Risk & Sensitive Areas, the land suitability map was produced and reclassified into 5 scored divisions from least suitable to most suitable areas. The results showed that about 15.87 of the area of Lavasan-e Kuchak Rural District is most suitable for establishment of tourism development.