Honduras and El Salvador, since their independences in 1821, have a conflicting relationship. After countless attempts to achieve a peaceful resolution in their frontier disputes, new factors - demographic, political and socioeconomical - are added to the nature of the relationship between these two states and would give rise, in July 1969, to a armed conflict known as - Soccer War - or Hundred-years War -. The immediate resolution of the Soccer War was accomplished by the Organization of the American States (OAS), through a coordinated action of four of its main bodies, that is, of the Inter-American Commission of Human Rights, the Permanent Council, the Secretary-General and the Meeting of Consultation of Ministers of Foreign Affairs.The main contribution of this study, brought up through the analysis of the OAS collective action in this case, leads to the conclusion that this organization has played three main roles, which have largely contributed to the immediate resolution of the Soccer War, namely (i) autonomous actor; (ii) modifier of state behavior; and (iii) forum/space for dialogue. Moreover, it is worth noting that the most powerful member of the OAS has not participated, nor direct or indirect, to the achievement of the immediate resolution of this conflict, which can be considered as an exception to the North-American interventionist politics towards Latin America in the 1960s.