This article presents a succinct analysis of two interrelated aspects: the methods and theories of interpretation followed by the Inter-American Court of Human Rights, and the "constitutional competences" that have emerged based on those methods and theories. The article explains that the interpretative methods followed by the Court have derived in an expansive view of the content of the rights protected by the American Convention of Human Rights and of the powers and attributions of the Court. As a result, the Court has understood some of its competences in a way that resembles those of constitutional courts (ie, developing similar notions to the doctrines of precedent and judicial review). The article argues that the approach taken by the Court has increased its possibilities to produce changes at the State level, but that has also created new challenges - theoretical and practical - regarding the limits that the Court should have as an international human rights tribunal that operates at a regional level.