Water scarcity and water availability put significant constraints on social and economic development, as well as deteriorate the quality of life. Today, the problem of water scarcity is the adverse result of ineffective water resources management and policies, as well as the unavailability of water in arid and semiarid countries. The causes for water scarcity can be institutional, socioeconomic, and climatic physical. The scope of this chapter is to provide a general overview of the status of wastewater treatment and reuse trends and practices under potential drought and water scarcity conditions. Although the background information on wastewater reuse and the recommendation for further research identified in this study are applicable throughout the world, the primary focus is on the implementation of reuse in regions under water scarcity. At the present time, several studies have been conducted on wastewater quality and for different purposes; however, there are no regulations of water reuse at the international level. With the development of tourism and global food markets, there is a need for sharing a common rationale for developing water reuse criteria. The overall objective of recycled water use is to lead to greater allocative and distributive efficiency of water resources and include this nonconventional measure in the technical solutions to combat drought and water scarcity to be finally adopted in the areas concerned.