Agroforestry research is central to developing methods for the sustainable use of natural renewable resources, evolving to address the needs of the coming century. It is now necessary to consolidate the scientific gains now being made in process-oriented research and to develop a policy framework to encourage the adoption of sustainable land use practices. Agroforestry plays an important role in conserving forest resources, reducing the need for deforestation. Further, if `forest' is broadly defined as tree cover, agroforestry will also increase the proportion of woody biomass in farming landscapes. The papers selected for inclusion in Agroforestry: Science, Policy, and Practice establish agroforestry as an interdisciplinary science focused on the practical imperative of assisting farmers, forest dwellers and landscape-level planners to achieve sustainable food, fuel and timber production into the 21st century.