Following the development of communicative, learner-centered approaches such as communicative language teaching (CLT) and task-based language teaching (TBLT), learner-learner interaction (i.e., peer interaction or PI) has become a prevalent type of interaction in L2 classrooms. However, much research has investigated PI among adult learners, with little targeting young learners (see Oliver & Adams, 2020; Philp et al, 2014 for recent reviews). Additionally, PI research has primarily focused on the issues and benefits of PI among adult learners, with no research, to the authors' knowledge, examining teachers' perceptions and practices of PI, particularly in EFL contexts. To address the gaps, this study explored how primary school teachers in Vietnam perceived and used PI in the classroom. The participants were seven experienced teachers from six primary schools across a Mekong delta province. The study used multi-methods, including classroom video recordings, field notes, semi-structured interviews, and stimulated recall interviews. Data was analysed following a theme-based approach with descriptive analyses of observational data. The findings show teachers viewed PI as manifesting itself in two forms: decontextualized form-focused PI (DFPI) and genuinely communicative PI (GCPI). Regarding GCPI, the teachers reported both benefits and drawbacks. Notably, their PI practices did not reflect their stated beliefs about PI use, with GCPI accounting for only a small portion of the time in a lesson. The study provides insights into PI as it is actually practiced in authentic classrooms and suggests some pedagogical implications for L2 classrooms of young learners.