Research on the routines of doctor-patient consultations has been conducted in language and culture concordant dyads and in dyads where either doctor or patient uses a foreign language; yet there is an absence of scholarly engagement with consultations where both participants are using a foreign language. In seeking to address this gap, this article reports on four doctor-patient consultations involving the use of English as a lingua franca. The data form part of a larger empirical study of communication in an Irish diabetes clinic. Microanalysis, informed by Interactional Sociolinguistics, Pragmatics and Conversation Analysis, reveals a range of interactive challenges rooted in language and cultural assumptions which impact on the management of the consultation routines. The findings emphasize the strength of the doctors' professional socialization and the challenges this poses for non-native-speaker patients.