Intersectoral and interstate conflicts over the use of limited water and energy resources are aggravating in all arid regions throughout the world, and particularly in the Aral Sea basin of Central Asia. Tremendous expansion of the irrigated areas to produce cotton starting from the 1960s led to a heavy dependence of the economies on irrigated agriculture. Irrigation development reduced environmental flows in the basin and caused a gradual desiccation of the Aral Sea, once the fourth largest lake in the world. The emergence of the five independent Central Asian states in the current territory of the Aral Sea Basin, after the dissolution of the Soviet Union in 1991, added new challenges for sharing basin resources. The resume of construction of Rogun dam, with a height of more than 300 m and active storage of over 10 km3, by Tajikistan in 2008 in the Vakhsh tributary of the Amu Darya River in upstream of Nurek reservoir led to fierce intergovernmental debates. Tajikistan intends to increase its national energy security and to gradually grow export revenues from electricity generation through this project with a maximum electricity generation capacity of 3600 MW. The country argues that the construction of the dam also increases water availability to downstream regions. In contrast, downstream Uzbekistan and Turkmenistan are concerned that inappropriate operation of the reservoirs by the upstream country may substantially harm irrigation benefits that are essential for the livelihoods of the majority of the population in these two countries. Despite many debates and controversial arguments by both parties over the results of the construction of the dam its impact of Rogun Dam on agricultural production and livelihoods in the downstream regions has not been assessed in detail. This study uses an integrated hydro-economic model to address the potential impact of Rogun Dam on downstream water availability and irrigation benefits.