Informed by current notions of dynamic bilingualism and the community of practice (C of P) framework, this study was designed as an ethnographic case study to explore peer collaboration in an English/Chinese bilingual program in a city in Western Canada. The main participants in the study were three Grade 5 English/Chinese bilingual students. The ethnographic data were collected for a whole academic year at school, in students' homes, and at community events through participant observation; field notes from the observation; semi-structured interviews and open-ended conversations with children, teachers, the principal, and parents; audio- and videotaped student--student and student--teacher interactions; and literacy artefact collection and analysis. Four main kinds of peer collaboration in the forms of helping, practising, sharing, and respecting were identified as significant factors that support these bilingual students' successful translingual practices and positive identities as language learners.