With the adoption of the Charter of the Organization of American States in 1948, the inter-American system that the countries of the hemisphere had been developing since the 19th century was institutionalized. In the last five decades, the OAS Charter has undergone various modifications that show the will of the Members of the American regional organization to ensure that the inter-American system adapts to changing circumstances. On the eve of the 21st century, the 50th anniversary of the OAS is accompanied by various signs regarding what protects the regional organization in the immediate future. In this special issue of the Revista Mexicana de Política Exterior, some of the main trends of the OAS are described and evaluated against the work carried out by it in the last half century, but above all, as a result of the skills it has acquired in the last decade.