Existing studies on doctor-client interactions have largely focused on monolingual encounters and the interactional effects and functions of the languages used in the communication between doctors and their clients. They have neither, to a large extent, examined the several codes employed in single encounters and their pragmatic roles nor given attention to communication at doctor-client first meetings in a bilingual or multilingual setting. This paper catalogues the generic structure of the interactions at first meetings in Nigerian hospitals and examines the pragmatic features and functions of the codes used by doctors and clients at the different units of the generic structure. Seventy-five audio recordings of doctor-client interactions were randomly made in selected state-government owned and private hospitals in South-western Nigeria in 2002, 2007 and 2009. Analysis of transcripts was based on theoretical aspects of code alternation, Levinson's notion of activity types and Sarangi's concept of discourse types. Four discourse stages characterise doctor-client interactions at first meetings in Nigerian hospitals: Opening, Diagnostic Interaction, Announcement and Closing. Two code selection types run through the generic structure of the interactions: non-strategic and strategic. Non-strategic choices are necessitated by cultural, institutional and linguistic routines. Strategic choices are characterised by context-shaping and context determined acts. Codes are selected at the non-strategic level to express phatic communion, indicate deference and display personal styles. At the strategic level, they are employed to accommodate dispreferred code choices, relax tension, flaunt competence, assure, save face, joke, reformulate and warn. (Contains 2 footnotes.)