Reuse of water in irrigated systems is a key component in design and management of irrigation systems. FAO and FutureWater developed a Guidance document, a Tool and a Training package demand for a better understanding of the role of reuse of water in irrigated agriculture systems. Those outcomes will support awareness rising, decision making and capacity building for water managers and decision makers. Agriculture is the most water demanding and consuming sector, globally responsible for most of the human induced water withdrawals. This abstraction of water is a critical input for agricultural production and plays an important role in food security as irrigated agriculture represents about 20 percent of the total cultivated land while contributing by 40 percent of the total food produced worldwide.