This paper provides an overview of what we call 'agroecological revolution' in Latin America. As the expansion of agroexports and biofuels continues unfolding in Latin America and warming the planet, the concepts of food sovereignty and agroecology-based agricultural production gain increasing attention. New approaches and technologies involving the application of blended agroecological science and indigenous knowledge systems are being spearheaded by a significant number of peasants, NGOs and some government and academic institutions, and they are proving to enhance food security while conserving natural resources, and empowering local, regional and national peasant organizations and movements. An assessment of various grassroots initiatives in Latin America reveals that the application of the agroecological paradigm can bring significant environmental, economic and political benefits to small farmers and rural communities as well as urban populations in the region. The trajectory of the agroecological movements in Brazil, the Andean region, Mexico, Central America and Cuba and their potential to promote broad-based and sustainable agrarian and social change is briefly presented and examined. We argue that an emerging threefold 'agroecological revolution', namely, epistemological, technical and social, is creating new and unexpected changes directed at restoring local self-reliance, conserving and regenerating natural resource agrobiodiversity, producing healthy foods with low inputs, and empowering peasant organizations. These changes directly challenge neoliberal modernization policies based on agribusiness and agroexports while opening new political roads for Latin American agrarian societies.