Co-teaching provides opportunities for children that cannot be produced by a solo teacher. However, building relationships between co-teachers, particularly in a cross-cultural setting, can be difficult. This study of early years teachers in a Hong Kong international school aims to consider the elements that facilitate a strong and productive co-teaching relationship and challenges that teaching teams encounter. The study utilizes qualitative interviews of 26 teachers to capture teachers’ perceptions of co-teaching. Findings suggest, that while teachers valued their relationships, the building and maintenance of a productive co-teaching relationship takes work, flexibility, and an openness to the perspectives of one’s partner. Copyright © 2021 Elsevier.