The main aim of this review is to examine agricultural water consumption in the Latin American and Caribbean (LAC) regions to understand how climate change will impact water availability and how the application of nuclear and stable isotope techniques can be used as tools for improving water use efficiency (WUE) for crop production. The status of agricultural water management in some LAC countries, such as Argentina, Brazil, Chile, Costa Rica, Cuba, Mexico, Panama, Paraguay, Peru and Uruguay, is also reviewed. In the LAC region, water consumption for agricultural irrigation ranged between 35% and 86% of the total available water. However, the WUE is very low in some LAC countries. Although the region, in general, has adequate water resources, there is still a need to improve WUE to increase the productivity of agricultural water. The impact of climate change in some LAC countries may lead to intensification and expansion of agricultural activity. In these areas, the WUE can be improved through soil and water conservation, minimizing soil evaporation (E), as well as through better irrigation management, especially by using an integrated approach on an area-wide basis to manage all land use activities and farming systems within an agricultural catchment. Nuclear and stable isotope techniques using Keeling Plot or IMB methods can play important roles in improving WUE in agriculture in LAC countries by providing information related to soil water losses for improving irrigation systems.