Schools respond to the complex needs of students exposed to traumatic and adverse experiences as part of an interconnected system of care that includes health care, child welfare, juvenile justice, housing and a variety of other community services. As legislation increasingly mandates inter-organisational collaboration, attention has turned to consider the ways in which educators and professionals of other disciplines and services interact. This paper analyses the partnership between an educator and a psychologist in the development, delivery and evaluation of a trauma-informed practice program for schools. Using a case study methodology, the research used qualitative analysis of the authors' reflections on their partnership to identify factors that have enabled and sustained interdisciplinary educational work. The findings highlight key elements of sustainable interdisciplinary joint work--including knowledge sharing, opportunities for expansive learning, adapting to changing working relationships and overcoming systemic barriers for collaboration. These themes are discussed in the context of implementing trauma-informed practices in schools.