Immigration in Western societies sometimes leads to medical consultations without any shared language between physician and patient. The intervention of a third party is required in such cases. This paper details a study of the role of such a third party. Conducted between 1998 and 2001 in French-speaking Switzerland by physicians and linguists, this research used several techniques of data production. In order to compare the viewpoints of the actors concerned (physicians, patients, and translators), researchers used questionnaires, semi-structured interviews, and focus groups. Analysis of these data reveals that professional translators perceive themselves as active participants who improve communication by bridging the gap between physician and patient. In the translators' perspective, this gap is both linguistic and cultural. On the other hand, most physicians and patients interrogated do not share this view. Points of view about languages can lead to miscommunication in medical settings in spite of a qualified interpreter's presence. This article discusses visions of the interpreter's role, which range from instrument to co-therapist.