During the International Symposium on Agroecology for Food Security and Nutrition, held at FAO headquarters in Rome on 18 and 19 September 2014, stakeholders representing governments, civil society, science and academia, the private sector, and the UN system gathered to discuss the contribution of agroecology to sustainable food systems. The Symposium provided an opportunity to share experiences, and build the evidence base on agroecology. These Proceedings bring together the lessons learned as well as scientific research and case studies of agroecology in practice. Agroecological experiences can be found in all regions, and agroecology policies are already in place in many countries in Latin America and Europe. Agroecological approaches have been also recognized by international bodies such as the Committee on World Food Security. FAO sees agroecology as a positive contribution to the eradication of hunger and extreme poverty, and a means to facilitate the transition to more productive, sustainable and inclusive food systems. FAO will continue to work with member countries to harness the benefits of agroecology by strengthening the evidence base and identifying and sharing examples of successful policies, strategies and approaches.