Professional identity formation is acknowledged as one of the fundamental tasks of contemporary medical education. Identity is a social phenomenon, constructed through participation in everyday activities and an integral part of every learning interaction. In this paper we report from an Australian ethnographic study into how medical students and patients use narrative to construct their identities. The dialogic narrative analysis employed focused on the production of meaning through the use of language devices in a given context, and the juxtaposition of multiple perspectives. Two stories told by students about their participation in patient care-related activities reveal how identities are constructed in this context through depictions of the relationships between medical students, patients and clinical teachers. These students use the rhetorical functions of stories to characterise doctors and patients in certain ways, and position themselves in relation to them. They defend common practices that circumvent valid consent processes, justified by the imperative to maximise students' participation in patient care-related activities. In doing so, they identify patients as their adversaries, and doctors as allies. Both students are influenced by others' expectations but one reveals the active nature of identity work, describing subtle acts of resistance. These stories illustrate how practices for securing students' access to patients can influence students' emerging identities, with implications for their future disclosure and consent practices. We argue that more collaborative ways of involving medical students in patient care-related activities will be facilitated if students and clinical teachers develop insight into the relational nature of identity work.