ABSTRACT This study proposes a model for sustainable education in fashion design through the development, implementation, and assessment of a specific curriculum. It employed the challenge-based learning (CBL) approach to facilitate the learning of concepts involving sustainability and sustainable fashion design, using a postgraduate course in South Korea as an illustrative case study. Qualitative research was undertaken, including observational evidence for describing students’ learning experiences and outcomes and assessing the effects on students’ sustainability competencies using a grounded theory-based interview analysis. The results demonstrate that CBL provides learners with sequential and organised design thinking procedures, compared to the traditional method in which defining each step of a design process is not crucial. CBL promotes the development of competencies in sustainability involving metacognition and metadisciplinary studies from students’ genuine experiences, contributing to creative and problem-solving skills. This study provides concrete evidence for CBL’s potential as a pedagogical model for sustainable fashion design.