The tourism system is a complex industry that include local companies, big corporations, and tourists. This dissertation will be focused on the role of transnational companies with a particular interest on Destination Management Companies (DMC). Even if they are considered as the giant of the tourism industry, there is still a lack of information on this topic. More precisely this dissertation will focus on the management of tourist flows, which, because of its ecological, social, and economic issues is an important and actual subject. Most of the scientific papers found on this topic show the implication of countries, regions, or local tourism companies in the elaboration of a management strategy. The main goal of this dissertation is to understand the importance for DMCs of setting up management of tourist flows strategy to engender a competitive advantage.