In this paper we provide an overview of the literature on understandings of drop out/opt out from science, technology and mathematics (STM) higher education programmes. After outlining the literature on students leaving higher education programmes in general, we then explore the research on drop out/opt out from STM programmes in particular, with an emphasis on research since 2000. We show that most of the research focuses on overcoming deficits in students' prior knowledge, but that a more specific focus on identities as an analytical framework for understanding young people leaving STM higher education programmes is also emerging. We show that it is important to shift from considering drop out as an individual problem for the student to regard it as a feature of the relationship between students and their study programmes. In the same way, measures to increase retention rates must shift from focusing on individual student adaptation to studies addressing institutional change. However, this change is difficult since it is entwined with fundamental conceptions of science and teaching. (Contains 1 note.)