Résumé : EU Migration Policy has progressively developed an external dimension, including third countries as actors involved in the accomplishment of its internal policy goals. This results in the outsourcing of borders control to the so called countries of ‘origin and transit’ and the signing of international agreements regarding readmission of unauthorized migrants. At the same time, Regional Policy regarding the Outermost Regions (ORs) of the EU emphasizes the need for further regional integration of these territories with their neighbouring countries. This paper aims to study the interrelations between the objectives of these two policy areas by concentrating on the case study of the Canary Islands archipelago. The interest of the choice lies, first, on the status of the Canary Islands as one of the nine European ORs, where transnational cooperation projects with Morocco, Cape Verde, Mauritania and Senegal have been conducted since 2000. Secondly, the geographical location of this archipelago makes boat migration a structural element and a political priority for the regional government. Accordingly, this research will focus on the consequences of EU securitization approach to migration for the regional integration of the ORs.To do so, this thesis explores first the EU external governance incentives-based model in a context marked by increasing interdependency. Further, the role of regions on the international arena is reviewed to later proceed by tackling the external dimension of EU Migration Policy, emphasizing on borders externalisation and readmission agreements. To finish, this paper analyses the case of the Canary Islands by testing the proposed explanatory framework for the particular case of sub-national external action as developed within the EU regional transnational cooperation policy frame.As major findings, this thesis has shed light upon the lack of policy coordination between the transnational programmes part of the EU regional policy and the external dimension of Communitarian policies relative to migration. Within an intertwined multi-level system of governance, every single actor located at different power levels has different priorities and national interests perform as a hindrance to policy coordination in the overall frame of migration policy. On the other hand, the lack of specific recognition of migration as a priority area for regional integration shows how the EU regional policy is characterized by the decoupling of different actors’ interests. The aims of external dimension of migration policy and those of the regional policy for ORs are contradictory in the case of the Canary Islands archipelago.