Postgraduate education has become increasingly crucial for nations in recent years, contributing to scientific, technological, and social progress. However, high dropout rates may undermine the benefits of postgraduate education. This study aims to identify which individual, academic, socio-economic, and institutional variables influence student attrition at the postgraduate level (master's and doctoral) through a scoping review. Using the PRISMA-ScR method, we analyzed 40 research articles for bibliometric insights and specifically examined explanatory variables for postgraduate dropout. Within the individual determinant, explanatory variables include nationality, gender, age, marital status, family support, family and work obligations, and motivation levels. Socio-economic variables encompass the student's income, employment status, and the national macroeconomic environment. In the academic context, key variables comprise prior knowledge, academic performance, student satisfaction, autonomy, self-efficacy, and research interest. Lastly, variables such as insufficient financial resources, institutional policies, teacher-student interaction, student support, academic infrastructure, and curriculum design play pivotal roles in the institutional realm. In conclusion, this study enhances our understanding of postgraduate dropout, offering valuable insights for the academic community and States to develop strategies that improve retention rates and reduce dropout levels in postgraduate education.