Objective:Characterize areas of interinstitutional cooperation and converging health agendas of the Pan American Health Organization/World Health Organization (PAHO/WHO), the Health Council of the Union of South American Nations (UNASUR), and the Amazon Cooperation Treaty Organization (ACTO) in South America based on social determinants of health. Methods:A qualitative study based on official documentary sources from the three organizations, using a comparative analysis of the health agendas of these agencies and the Rio Political Declaration on Social Determinants of Health (2011). Information was systematized using an analytical matrix that identifies convergences in the respective agendas. Results:Development of the health agendas of these agencies is influenced by various international forces such as Member States' foreign policy, international cooperation strategies and models, and the institutions' political and strategic guidelines. These agendas reveal efforts to strengthen blocs, cooperation mechanisms, and coordinated programmatic actions. Conclusions:The agendas of PAHO/WHO, the UNASUR Health Council, and ACTO point towards opportunities for convergence in various programmatic areas, emphasizing social determinants of health. Based on the overall agreements of the Rio Declaration as an analytical framework with recommendations in five decision-making spheres, structural cooperation actions can be carried out in the region's countries, jointly mediated by these agencies.