Due to the increasing demand for metals, the extractable grade of metal deposits has been decreased and caused an increase in the amount of tailings. Increase in the volume of tailings needs proper attention to tailings disposal, the establishment of tailings dams, water consumption and prevention of environmental and groundwater pollution. Since tailings disposal consists of many stages such as discharge, thickening technology and place, and transportation, selection of the best disposal method is a complicated task. Nowadays, decision-making methods are widely used and they are very reliable and efficient. Therefore, a model based on fuzzy Analytic Hierarchy Process (AHP) has been developed in this study to optimize the tailings disposal method selection. In the model, 21 criteria and a wide range of alternatives have been introduced. The model has been applied for Sangan Iron Ore Project (SIOP). The concentrator plant of SIOP will produce 75 million tons of tailings during the mine lifetime. Since the current disposal method wastes 1.5 million cubic meters of water annually and the fact that the project is located in a dry region, the proposed model has been used to investigate other options and the results shows the filtered technique is the best alternative.