Agricultural development depends on innovation, but creating the conditions that allow smallholder farmers to innovate and to use new technologies and practices is one of the major challenges that agricultural policy-makers face. Investing in agricultural research is important to reach this goal, but it is not sufficient. The concept of the “Agricultural Innovation System” draws attention to wide range of actors and organizations from the public, private and civil society sectors that are involved in bringing new agricultural products, processes and forms of organization into economic use. This concept also acknowledges the role of the institutional and policy environment that affects agricultural innovation. IFPRI’s research on the governance of agricultural innovation systems aims at developing analytical tools and methods to identify the most binding constraints to innovation in smallholder-based agriculture, and to assess strategies to effectively address these constraints.