This study employs conversation analysis (CA) and membership categorization analysis (MCA) in an exploration of the interactional organization of talk between doctors and the mothers (or the female guardians acting as “proxy mothers”) of HIV-positive child patients being treated at a paediatric hospital in the Western Cape, South Africa, in 2003. The analysis focuses on how the HIV paediatric consultation is co-constructed between the doctor and the mother/guardian, and how interactional choices on the part of the participants shape the course of the consultation. Specific attention is placed on how participants orient to, hear, respond to and coconstruct the category of “mother”, along with the emergent inferences of what constitutes “good mothering” in the context of pursuing the wellbeing of the HIV-positive child who - as it emerges in certain cases - has evidently been infected by the mother in the first instance. As its core focus, this study examines how orienting to “good mothering” is done - in a moment-bymoment, collaborative and co-constructed manner – in the immediate course of the doctor/mother/guardian consultation. This involves considering the interplay of shifts in orientations to “motherly responsibility” and “doctorly responsibility”, and how these shifts are collaboratively activated, negotiated and responded to, as the consultation proceeds.