The availability and quality of clean water in many regions of the world is increasingly threatened by overuse, misuse and pollution. In this context, the relationship between forests and water is a critical issue that must be accorded high priority. This thematic study on forests and water was developed in the context of the Global Forest Resources Assessment programme. It is directed to a broad range of technical experts, scientists and decision-makers, particularly national authorities, and presents recommendations on giving more attention to the role of forests and trees in water protection and management at the national level. It also calls for stronger collaboration between the water and forest communities.