Siting of secured landfill is difficult because of the complexity of technical and social aspects. Technically, the appropriate tool for secured landfill sites analysis should be applied in the siting procedure. This study aims at developing a comprehensive tool to facilitate the analysis of secured landfill sites. It integrates Geographic Information System (GIS), Expert System (ES) and Analytic Hierarchy Process (AHP) into a packaged tool. The GIS represents spatial data, ES represents a knowledge base about secured landfill siting, AHP was applied for ranking of candidate sites and a user interface was developed to make this tool a user-friendly graphical system. The use of this tool was illustrated by identifying suitable sites for secured landfill in Khon Kaen Province, Thailand.