This paper analyses the forms of mediation in interlinguistic interactions performed in Italian healthcare services and in contexts of migration. The literature encourages dialogic transformative mediation, empowering participants' voices and changing cultural presuppositions in social systems. It may be doubtful, however, whether mediation can actually be effective in changing the status quo of social systems. My research analyses video-taped interpreter-mediated interactions, focussing on the mediators' translation activity, and on its relationship with the cultural presuppositions in the medical system. While occasionally a dialogic transformative mediation is achieved, mediation mainly supports a doctor-centred communication, preventing the empowerment of linguistic and cultural minorities.