This article describes the results of a qualitative multiple case study investigation of the experiences of preservice teachers during a teaching practicum in Hong Kong. The study uses in-depth interviews with pairs of student teachers and their school-based supporting teachers to understand how the former positioned themselves as particular types of teachers through mutual interactions with other communities of teachers during a teaching practicum. Three case studies explore the ways in which the pairs of student teachers not only supported each other within the context of a teaching team, but also jointly deployed strategies to establish and defend the values of teaching and learning that were afforded a premium by their community of preservice teachers. The results underscore the importance of investigating relations between different communities, such as student teachers, school-based teachers and school authorities if the learning goals of the teaching practicum are to be attained. Implications for how relations that foster the professional development of all teachers within and across different communities during a teaching practicum might be achieved and sustained are discussed and implications for future research considered.