Abstract:The growing international food demand, the call for plant proteins to improve sustainability, the technological possibilities for sunflower protein ingredients, and the prominent role of Brazil in the world agricultural supply constitute the research background of this article. The aim is to analyze the process of establishment of the major sunflower agri-food chain in Brazil, seeking to support the future development of new sunflower chains to meet an expected increasing demand for high-quality sunflower proteins. A case study research design was applied, involving interviews with stakeholders from the input, farming, and processing segments. Moreover, the case analysis was guided by an analytical framework that regards the agri-food chain establishment as an entrepreneurial process. The findings show that the successful process of the sunflower agri-food chain establishment in Mato Grosso (MT) stems from a set of interconnected driving forces composed of entrepreneurial skills, social network, resource availability, and crop suitability. Furthermore, the analysis indicates the potential for the development of new sunflower chains among soybean farmers from other regions in MT, especially if new sunflower protein food ingredients lead to higher sunflowers prices, which would make this crop economically more attractive. Finally, this case study suggests that the collective establishment of agri-food chains is a challenging endeavor, especially if conducted by outside actors.