The Kingdom of Saudi Arabia is experiencing an acute shortage of freshwater and is now looking for new water sources. In 2009, domestic water demand was 2,330 million cubic meters (MCM); about 730 MCM domestic wastewater was treated and 325 MCM of the treated wastewater (TWW) was reused. The remaining wastewater is typically discharged into the Arabian Gulf, Red Sea, sand dunes and wadis. These discharges can affect the environment and groundwater quality. This study investigated TWW reuse potential and developed a fuzzy multistage hierarchy framework for evaluating TWW reuse in Saudi Arabia. This research demonstrates that comprehensive reuse of TWW can replace approximately 1,631 MCM/yr of groundwater extraction. Reuse of TWW may produce approximately 654,500 tons of wheat (175 million US$), which is 20.5% of the national wheat demands in 2011, while the environmental pollution can be minimized. In this framework, four factors: cost, risk, benefits and social acceptance of TWW reuse were considered as the main criteria. These criteria can be evaluated using basic criteria and priority matrices following the hierarchy structure. The framework incorporates uncertainty in evaluating TWW reuse. A hypothetical case study is presented to apply the framework.