This conceptual paper explores the characteristics of education for sustainable development (ESD) within urban secondary schools. Despite the discourse about the importance of sustainability, there has been a lack of research on this topic. The authors employed theory synthesis, which resulted in a concept for Education for Sustainable Development in Urban Contexts (ESDUC). This presents a comprehensive view on the interconnected characteristics that facilitate the successful implementation of ESD in urban secondary schools, (1) developing sustainability competences among both students and teachers, encompassing intercultural competences for teachers and self-regulating skills for students, (2) utilizing teaching methods that are both transformative and culturally responsive, (3) engaging the wider community in the educational process, and (4) shifting the school culture toward embracing diversity and adopting a whole-school approach. This study is valuable for researchers and urban secondary schools seeking to effectively integrate ESD into their educational framework.