Are the available water resources sufficient to produce food for the growing world population while at the same time meet increasing municipal, industrial and environmental requirements? Projections for the year 2025, presented by different research groups at the second World Water Forum in The Hague, show an increase in global agricultural water use ranging from 4 to 17%. Estimates for the growth of total withdrawals, including domestic and industrial sectors, vary from 22 to 32%. This range is the result of differences in model structure and assumptions. Although these analyses were instrumental in raising awareness concerning the extent of present and future water scarcity problems, they raise many questions, which remain largely unanswered. The questions relate to the impact of water- and food-related policies on global and regional water scarcity, food production, environment and livelihoods through the year 2025. The International Food Policy Research Institute (IFPRI) and the International Water Management Institute (IWMI) embarked on a joint modeling exercise to address these questions. This paper lays out the issues and discusses the methodology. During the 18th ICID Congress in July 2002 at Montreal, preliminary results will be presented. Copyright © 2003 John Wiley & Sons, Ltd.