In Spain there is a number of examples of the direct reuse of treated wastewater, located in areas with water resource deficits. Agricultural irrigation is the most widespread use, accounting for 85% of the total volume. The reuse of water in agricultural irrigation has generated many benefits, such as contributing to alleviate the water deficit in many zones; improving resource management; serving as an additional source of fertilization; and, in some cases helping to recharge aquifers. Current water reuse initiatives and the potential for future actions are concentrated fundamentally on the Mediterranean coast, the southern Atlantic coast and in the archipelagos of the Balearic Isles and Canary Isles. This paper discusses how, in these zones, there are increasing expectations regarding the reuse of treated effluents, due on the one hand to the great demand for water resources from growing urban areas, tourism and a booming agricultural sector, and on the other hand to the difficulty in obtaining resources due to the increasing distances between cities and water supply sources, the difficulty in finding locations for new regulating reservoirs, the deterioration of aquifers, and the frequent droughts that affect these zones. Includes figures.