Groups are central to problem-based learning (PBL) and educational and professional outcomes relevant to clinical education. However, PBL groups in practice may differ from theoretical conceptions of groups. Therefore, this study explored students' understandings of the purpose and value of PBL groups for their learning. We conducted a naturalistic study with novice (first-year) students at two dental schools (Australia, Ireland), using observation and interviews analyzed thematically. Students constructed PBL learning as individual knowledge gain, and group purpose as information gathering and exchange; few students acknowledged the learning potential of group processes. Group value depended on assessment and curriculum context. Findings are explained in relation to how students' epistemologies and perceptions of their learning contexts shaped group behaviour. Implications for health professional education practice are considered.