Researchers from different social sciences are increasingly interested in studying the role of institutions in regional development. Nevertheless, from the perspective of regional tourism development analysis, the role of institutions has been explored limitedly. Based on the institutional thickness approach, this study analyzed the role played by institutions in regional tourism development through a qualitative research procedure applied on a Latin American region. The study examined the institutional presence, the levels of interaction, the structures of domination and/or coalition patterns, and the common agendas in 28 institutions related to tourism in the region of Antioquia, Colombia. Results from this empirical analysis show that institutions play a decisive role in regional tourism development for reasons such as the allocation of economic resources, leadership, and interaction among stakeholders. Knowing these dynamics can be useful to boost better management and planning of tourism destinations throughout governance, coordination, and common agendas, and to enrich the debate on regional tourism development.