An appropriate institutional set up is essential for efficient transboundary flood management in the Rhine basin, particularly in view of future uncertainties like climate change. Flood management factors are identified based on a historical comparison in the Netherlands and Germany. They include differences in the perception of the problem and how to solve it; in the understanding of key items and how to address them; in administrative responsibilities and the political will to act. Suggestions are made to improve cooperation, in particular to generate a common problem perception and problem analysis, to develop a common vision for future flood strategies and to create a network of discussion platforms to promote social learning and to prepare, decide and implement flood management issues. © IWA Publishing 2007.