Most readers of this essay will likely have written a PhD thesis, will be in the throes of writing one or perhaps be aspiring to write one. There is a huge literature on the practice and experience of PhD research: on designing a thesis, on writing and research, on the student-supervisor relationship, on the doctoral student experience, and so on. In this essay, however, I reflect on a specific question less often asked: in what ways does a PhD thesis live on beyond the time when it can only be thought of as ‘work in progress’? I develop an answer to this question along four dimensions: the material, instrumental, epistemic and personal afterlives of a PhD thesis. For this reflection I use my own PhD thesis, awarded in 1985, as the case study. While the essay is therefore autobiographic, it is intended to provoke more general considerations about the longevity of PhD theses and their formative role for their authors and their authors’ subsequent careers. While a PhD thesis can be understood as having a variety of afterlives, those that matter the most are perhaps also those that are less easily recognised.