The sociological study presented in this paper focuses on the role of local institutions in the structuration of international bonds of friendship. The role of cities as actors in the international relations' system has been questioned in the literature since the 60' (Boulding, 1968). In a more institutional perpspective, studies have also taken into account the importance of subnational entities in the definition of foreign policies, but mainly in federal States (Duchacek, 1986 ; Duchacek, Latouche, Stevenson, 1988, Hocking, 1993, Belanger, 1995, Phelippart, 1998). Yet, even when initiatives of municipalities have been studied for themselves (Hobbs, 1994), friendship initiatives have rarely been the main centre of interest (except Khalaf, 2002). The following paper will focus on the structuration of bonds of friendship at the local level, and stress the importance of institutional configurations in this process.