BackgroundPeer review in Team-based learning (TBL) exists for three key reasons: to promote reflection on individual behaviours; provide opportunities to develop professional skills; and prevent ‘free riders’ who fail to contribute effectively to team discussions. A well-developed process that engages students is needed. However, evidence suggests it remains a difficult task to effectively incorporate into TBL. The purpose of this study was to assess medical students’ ability to provide written feedback to their peers in TBL, and to explore students’ perception of the process, using the conceptual framework of Biggs ‘3P model’.MethodsYear 2 students (n = 255) participated in peer review twice during 2019. We evaluated the quality of feedback using a theoretically derived rubric, and undertook a qualitative analysis of focus group data to seek explanations for feedback behaviors.ResultsStudents demonstrated reasonable ability to provide positive feedback, but were less prepared to identify areas for improvement. Their ability did not improve over time, and was influenced by the perceived task difficulty; social discomfort; and sense of responsibility in providing written feedback.Conclusions To increase student engagement, we require a transparent process that incorporates verbal feedback and team discussion, with monitoring of outcomes by faculty and adequate training.