Resumen: The purpose of this paper is to find out what effects the declaration of unconventionality made by the Inter-American Court of Human Rights within a legal system produces, in those cases in which the contested norm is absolutely incompatible with its criteria, not being possible harmonization between them through the so-called “according interpretation”. For it, the doctrine that has dealt with this issue is analyzed, as well as the relevant jurisprudence emanating from this international tribunal.