This Policy Research Brief draws on case studies in Brazil and Cuba, as well as analytical papers on agroecology in theory and practice, to contribute to the discussion on how countries can pursue a national agricultural development model based on agroecology. Drawing on the case study experiences, the institutionalisation of an agroecology-based farm system must come from both the state—with support services and investments—and society—with farmer-to-farmer networks and socially inclusive participatory organisations. In Cuba, with the government lacking adequate resources, the agroecological movement was largely based on societal actors in the form of rural labour organisations mobilising and creating farmer-to-farmer networks. Although born out of necessity, the Cuban experience exemplifies the importance and effectiveness of farmers using social capital to innovate and overcome difficulties with alternative forms of production. In Brazil, although rural labour organisations are increasingly gaining influence and participating in policy discussions, the state’s comprehensive agricultural policies provide substantial support, extension and investment for family farmers. The challenge is to scale up these programmes and create increased incentives for agroecology-based production within the current policy framework.