The teachings of the most highly qualified publicists in international law explain to us that the judicial decisions, dictated by the international courts, only constitute subsidiary source of international law; and these judgments only have effects for the parts in litigation and with respect of the case that has been decided. The Inter-American Court of Human Rights (Inter-Am Ct HR) has arranged that member states must realize a judicial review of conventionality that confirms the domestic law is in concordance with the jurisprudence developed by the Inter-Am Ct HR. The control of conventionality supposes instituting the decisions of the Inter-Am Ct HR as sources of internal law, under a direct application and restricting the field of sovereign decision of states. In order that the control of conventionality could be consolidated in the inter-American system of human rights, it is pertinent that member states possess an express constitutional authorization and incorporate in a differentiated way the margin of appreciation doctrine. Likewise, it is suitable that the Inter-Am Ct HR by means of new mechanisms of reparation can explore different forms of inter-institutional dialogue with the national authorities.