This paper explores current and future issues of water availability and use in one of the world's major wine-producing areas, Mendoza Province in Argentina. The region is located close to the Central Andes and is characterized by an arid to semi-arid climate, which exacerbates pressures on land-use and water resources for wine production. The principal supply of water originates in the snow and ice fields of the nearby Andean peaks. Already under stress today, the environmental, economic and societal structure of the region, highly dependent on the wine industry, is likely to be vulnerable to climate change in the course of the 21st century. In this study, the possible impacts of shifting temperature and precipitation patterns and climate variability linked to extreme events and El Nin˜ o/Southern Oscillation ENSO on water resources in the region and consequently on the wine industry will be investigated. While climatic factors already today exert a major control on water availability, water use is also shown to be influenced by non-climatic factors, in particular overexploitation of the resource and a certain degree of opacity of policies related to water rights and water allocation. Climate model results for the future suggest that there may be important changes in the quantity and timing of stream flow, highly dependent on the Andean cryosphere where many glaciers are already rapidly shrinking today. The direct impacts of a changing climate on wineries include extreme events and also decreased water availability for irrigation in the long term. In view of the importance wine as a major income earner for Argentina, public water policies will need to address both the issues of unreliable current water governance practices and the adaptations necessary to cope with a changing climate.