The present work investigates the localization of an international norm in Brazil, the right to the truth, through the establishment and practice of a truth commission. Established in May 2012, the National Truth Commission inserts Brazil into an ever-expanding list of states that resort to this mechanism in order to deal with past human rights violations. Guided by an international norm - the right to the truth -, the establishment of truth commissions is a practice that has spread along with other transitional justice mechanisms and that perceives the confrontation with the past as a way to build a better future. Nevertheless, the localization of this norm may occasionally encounter resistance from divergent local norms. From a constructivist perspective of international norms localization, the aim of this study is to analyze the political and legal constraints faced during the insertion of the right to the truth into Brazil s normative and institutional frameworks, paying particular attention to the process that lead to the creation and the actual work of the National Truth Commission from 2012 to 2014. This dissertation argues that the process of localization faced political and legal opposition and that it was up to local actors to reinterpret the international norm in order to adapt it effectively to local demands.