Despite growing enrolment in postgraduate education, completion rates remain low, often falling below those of undergraduate programmes. This disparity has raised concerns about the adequacy of current retention strategies, which are frequently designed with undergraduate students in mind and may overlook the specific needs of postgraduate learners. Master’s students often face distinct challenges, including balancing professional responsibilities, academic demands, and family obligations, all of which contribute to a heightened risk of dropout. This study investigates the institutional factors contributing to non-completion in master’s education through a qualitative case study at a public higher education institution in Portugal. Using an adapted Delphi methodology, data were collected through semi-structured interviews with first-year students and follow-up interviews with postgraduates to validate and deepen the findings. The results reveal three key areas influencing student retention: the early alignment between coursework and dissertation topics, the consistency and support provided by thesis supervisors, and the degree of flexibility in institutional scheduling and workload management. Based on these insights, the study proposes practical recommendations such as structured dissertation timelines and increased opportunities for academic engagement, including participation in conferences. These measures can help higher education institutions reduce attrition and improve the postgraduate experience by aligning academic structures with students’ lived realities.