Abstract Providing the water needed to produce food for more than 9 billion people by 2050 seems simple: agriculture must produce more food with less water. However, three complex issues are involved: First, water, food production and rural development do not have a simple correlation. Second, there are interactions between processes at local, basin and global scales. Third, change involves people in complex networks of institutions. The Challenge Program on Water and Food brings together agriculturalists, hydrologists and development specialists in a global-to-local programme that focuses on change through institutions. We believe that this scale, complexity and involvement are necessary to deliver plausible change. Keywords: Challenge ProgramwaterfoodagricultureBasin Focal Projects Acknowledgements We would like to acknowledge the support of the Challenge Program on Water and Food. We also acknowledge the important role played by many people in bringing this paper to fruition, among them: Basin Focal Project leaders and team members, participants in fora for planning and monitoring BFP progress and participants in the planning of CPWF Phase 2.