When student plagiarism occurs, academic interest and institutional policy generally assume the fault rests with the student. This paper questions this assumption. We claim that plagiarism is a shared responsibility and a complex phenomenon that requires an ongoing calibration of the relative skills and experiences of students and staff in response to their respective personal and institutional pressures. This paper examines how teaching staff understand their responsibility in addressing plagiarism. Our findings suggest that a staff member's general understanding of their role in preventing plagiarism is related to their awareness of different contexts and sites across the institution (e.g., assessment task, course design, programme structure and institutional policies) and their ability to integrate them. Accordingly, this paper proposes a framework that integrates the differing roles of staff in plagiarism prevention and offers a stronger basis for the analysis and development of strategic action by schools and departments.