Teaching human rights is a challenging and complex endeavour that requires the translation of policy into practice. Practitioners working in the implementation of Human Rights Education (HRE) programs need to convert the abstract content of human rights and general guidelines offered in human rights policies into contextually relevant teaching practices that respond to learners' needs. The challenge increases in contexts such as Mexico where the national policy aims to incorporate the robust legal framework on human rights and, at the same time, provide a blueprint to address the current crisis of violence and human rights violations involving cases of torture, forced disappearances, unlawful killings and assassinations across the country. HRE has gained widespread support across governmental and non-governmental organizations in the country and is nowadays the most recurrent strategy to achieve both goals: consolidating the legal framework of rights, as well as combatting and preventing further human rights violations. Despite the current momentum of HRE in Mexico and the high expectations towards it, there is little systematic information on how it is implemented or the role of practitioners in this process. Previous research in HRE has failed to give an in-depth account of the role of practitioners' agency and decision-making for policy implementation, particularly in contexts where these rights are not upheld. To fill this gap in the literature, this article explores how practitioners teaching in Human Rights Education (HRE) programs in Mexico build their professional agency--despite the adverse context and institutional constraints--to better understand how they navigate the complexity of translating policy into practice and the scope and limitations of their individual capacity as mediators in the process.