This paper investigates aphasia speech therapy as a particular form of institutional interaction dedicated to the recovery of language and communicative abilities in adult speakers. This specific form of social interaction involves both health and pedagogical issues, by presenting features generally observed in instructional settings. The paper investigates these features by focusing on the interactional and sequential organisation of naming activity -that is, the activity of naming a card. Through detailed analyses of participants' multimodal conduct, it is shown that this task (e.g. producing a specific linguistic item) is collaboratively accomplished. This defends a conception of the therapy as a socially situated and collaborative process, whose dynamics must be investigated taking into consideration participants' multimodal resources. By focusing in particular on the cueing practices used by the therapist in order to assist the client's word retrieval and production of the target item, the paper shows that these practices are strictly dependent on the micro-details of interaction, on the client's audible and visible conduct, and as such are incrementally and locally occasioned. It therefore highlights the active role played by the client in negotiating the assistance needed by the therapist and, more broadly, in co-constructing the therapeutic process.