This study provides a comprehensive review of the phenomenon of students dropping out from tertiary education. Student withdrawal is the result of a long decision-making process and complex interaction between several determinants. We first provide an overview of definitions, theoretical models and perspectives of dropping out. Referring to previous theoretical and empirical evidence from a wide range of disciplines, we then focus on a detailed discussion of determinants affecting the decisions of students to drop out. There are three main reasons for students to leave the higher education system without a degree. These are 1) the national education system, e.g., the country's financing policy, 2) the higher education institutions, e.g., the type of institution or teaching quality, and 3) the students themselves, with this last aspect subdivided into a) pre-study determinants, such as the secondary school type, and b) study-related aspects, such as working while studying. Based on these findings, we discuss the implications for further research, especially the application of modern data mining techniques on comprehensive data sets covering a wide range of relevant determinants which may lead to new insights into the dropping out process. The results will provide helpful tools for universities wishing to implement early warning systems and to support students at risk, at an early stage of their study.