The paper explores the professional practice of “cultural mediation” in the Italian context. This activity is taken here as a vantage point from which the dynamics of identity projections can be observed, as they emerge from a real-life interaction. The analysis is carried out on a recorded and transcribed encounter involving three participants: a service provider working for a Foreigners Advice Bureau run by the municipal authorities of a major Italian city; a French-speaking asylum seeker from Cameroon; and a Moroccan mediator. The encounter is characterised by a high degree of interactional heterogeneity; triadic configurations where the mediator acts as “interpreter” alternate with parallel conversations and with long dyadic exchanges between the mediator and the service user, in the absence of the service provider. Within this changeable participation framework, the interlocutors’ discursive choices are closely examined. The theoretical framework brings together two complementary paradigms, a linguistic-interactional and a socio-psychological one. The resulting discussion, which revolves around the concepts of “role”, “discourse”, “position” and “narrative”, reveals cultural mediation as an area of instability, where competing identities are interactively constructed and reconstructed.