The paper presents partial results from an ongoing research on communication in the medical setting. The aim of the paper is to show how the institutional context can affect argumentation by focusing on the activity type of medical consultations. In order to achieve this goal, the paper is structured in four sections. The first one offers a description of the institutional dimension of the medical consultation set within the cultural domain of the Italian National Health Service. In the second section, this description is completed by outlining also the interpersonal dimension of the context. The third section presents partial results obtained through the analysis of a collection of medical consultations. The analysis was conducted by selecting the argumentative extracts from the consultations and by describing the argument schemes used both by doctors and patients. The analysis shows that the persuasive strength of argument schemes varies depending on the way they are used in the different institutional contexts. In particular, the specific features of the institutional contexts constrain the effectiveness of the argument scheme by ‘commanding’ context-specific premises, or endoxa. Therefore, those who have a better knowledge of the context will be able to use the various argument schemes more successfully because they will be able to refer to the most ‘context-relevant’ premises. A development of the research should include more data in the analysis and also foresee the possibility for a comparison with data collected in different cultural contexts.