Objective — The medical interview has important diagnostic and therapeutic functions and requires the integration of doctor-centred and patient-centred interviewing techniques to collect accurate and complete biopsychosocial data from the patient. Analysis of the interaction between patient and doctors which occur during the medical interview allow to evaluate physicians' interview techniques and to eventually improve them. Objective — 1. To review different Interaction Analysis Systems (IAS) used to describe doctor-patient communication in terms of clinical relevance, observational strategy, reliability and behavioural and verbal contents. 2. To critically evaluate these IASs on the basis of their relevant research outcomes. Method — Previous reviews on interaction and keywords for Medline research (HealthGate) listed above were utilised to collect the relevant literature. Results — Seventeen classification systems were identified and ten were discussed in a chronological order. Starting from a general sociological or psycholinguistic approach, the IASs over the years have became more specific and detailed, focusing more and more on the medical interview and on specific topics, such as cancer or hospital medical consultations. Conclusions — When studying interactions in general practice medicine, it is important to define the significant units of interaction which allow to identify a «patient-centred approach», since this is relevant not only for obtaining reliable and complete medical and social data, but also for the recognition of patients with emotional disorders and their correct diagnosis. Listening to the patient and facilitating the expression of emotions is an important aspect of patient education too, as patients learn that talking about psychological problems to their physician is appropriate and may be therapeutic.