This research presents an integration of GIS with fuzzy logic for landfill site selection in the Iskandar region (latitude: 1° 26΄ 23.45΄΄ N & Longitude: 103° 37΄ 21΄΄ E) in Malaysia alongside with the customized GIS application for doing this study. Landfill selection in an area is a critical issue in the decision making process because of its great impact on the environmental health, ecology and economy of the region. Several factors have considered in the siting process, including topography and geology, administrative boundaries, cadastral, hydrology and road network, fuzzy multi criteria decision analysis and GIS are integrated to solve the problem of landfill site selection and based on our criteria to develop a ranking of the potential landfill areas. At the first step, GIS digital map overlay techniques were used (customized GIS application), in order to find the suitable sites. The second step was a fuzzy logic approach that the system ranked sites on a scale of 0-100%, with 100% being the most appropriate one. At the third step the potential sites that were selected from the last step will be ranked by Analytical Hierarchy Process (AHP) in order to prioritize the potential sites.