Designing the training of future teachers through holistic and interdisciplinary visions is vital to developing coherent contents, epistemologies, and methodologies that put Education for Sustainability into action. The research presented here analyzes the teaching guides from the curriculum for the Master's Degree in Secondary Education Teaching at the Universitat de València (Spain). A collaborative study on the inclusion of sustainability in a selected sample of teaching guides was conducted from an Action/Research methodological approach. The study includes an analysis of the competences identified by the United Nations Educational, Scientific and Cultural Organization (UNESCO) and their expected contribution to the 17 SDGs in the United Nations 2030 Agenda. The results of this research point to the need to promote collaborative work across disciplines in order to engage teachers in the transition to sustainability and encourage them to participate in the research process.