Purpose: Education for sustainable development (ESD) is one of the challenges engineering education currently faces. Engineering education needs to revise and change its curriculum to integrate ESD principles and knowledge. Problem based learning (PBL) has been one of the main learning pedagogies used to integrate sustainability in engineering education. However, there is a lack of understanding of the relation between ESD and PBL principles and the ways in which they can be integrated and practised in the engineering curricula. This paper aims to investigate the relation between PBL and ESD and the ways in which they are integrated and practised in the engineering curricula. Design/methodology/approach: The study starts with a review of the literature concerning ESD and PBL theories where relations between both are defined. The literature review is followed by an empirical work in which the PBL and ESD relations are investigated in relation to the PBL engineering curricula. The empirical work involves two engineering master programmes from Aalborg University, Denmark, while documentary analysis and interviews are used as methods for data collection. Findings: The results show that even though PBL and ESD share common learning principles, their practice presents limitations that challenge the full integration of sustainability, namely, the crowded, strict and academic-centred curriculum, the struggle to balance different contexts with professional, interdisciplinary and collaborative knowledge and the tacit presence of sustainability. Originality/value: The existence of a PBL curriculum at institutional level, such as at Aalborg University, enables investigation of how the PBL and ESD principles are practised, highlighting the limitations and potentials of integrating sustainability in the engineering curriculum.