Purpose: There is broad consensus that the implementation of education for sustainable development (ESD) requires the consideration of geographical and cultural contexts. Despite such an agreement at a theoretical level, there is so far an apparent lack of practical experiences and solid research on approaches that effectively manage to engage professional educators in higher education with ESD in the context of a developing country from the Global South. This paper aims to address this gap and present a case study from a pilot professional development program (PDP) that sought to implement and mainstream ESD among Ethiopian colleges of teacher education (CTEs) and theological seminaries (TSs). Design/methodology/approach: The research presented is based on the methodology of evaluative case study research in ESD. It analyzes the PDP’s specific objectives with regard to capacity and structure building, describes major activities implemented and how these relate to the objectives and explores major outcomes of the PDP. Findings: The paper presents a comprehensive training curriculum aimed at addressing ESD in Ethiopian CTEs and TSs in a whole-institution approach. Results suggest that the PDP’s approach to combine human capacity and institutional structure building was effective in supporting the implementation and mainstreaming of ESD in CTEs and TSs in Ethiopia. Originality/value: This case study presents original research on a pilot Ethiopian PDP that was implemented in collaboration with two academic institutions from Ethiopia and Germany.