The article contributes to the discussion of writing at doctoral level, which has lately been of interest in higher education literature, by approaching doctoral theses "as texts" and by highlighting textuality and rhetoric in doctoral writing, issues which have been marginalised in the discourse to date. In this paper I analyse the use of metaphor in two completed doctoral theses, highlighting its use as a rhetorical device which enables these thesis writers to conceptualise their research by drawing on knowledge beyond academic contexts, investing the thesis with individual and cultural significance. Supervisors and teachers of writing at doctoral level, as well as thesis writers themselves, are encouraged to pay greater attention not only to the role of metaphor in thesis writing but to the mechanisms used in the production of meaning in the thesis text more generally.