Agriculture and forestry are too often treated separately, yet these two sectors are often interwoven on the landscape and share many common goals. The age-old practice of growing crops and trees together was ignored or bypassed in the single-commodity paradigm of agricultural and forestry development. Thanks to 25 years of efforts, agroforestry – the integration of multipurpose trees into farming systems – has now become a robust, science-based, integrated discipline. Agroforestry offers a unique set of opportunities for alleviating poverty and arresting land degradation, and providing ecosystem services in both low-income- and industrialized nations. These practices are particularly suitable for resource-limited conditions and lower-input situations, which cover an estimated 1.9 billion hectares of land and 800 million people in developing countries.