The traditional paternalistic model of medical decision-making, in which doctors make decisions on behalf of their patients, has increasingly come to be seen as outdated. Moreover, the role of the patient in the consultation has been emphasised, notably through the adoption of 'patient-centred' strategies. Models that promote patients' active involvement in the decision-making process about treatment have been developed. We examine one particular model of shared decision making [Charles, C., Gafni, A., Whelan, T, 1997. Shared decision-making in the medical encounter: what does it mean? (or it takes at least two to tango). Social Science & Medicine 44, 681-692.]. The model has four main characteristics. These are that (1) both the patient and the doctor are involved, (2) both parties share information, (3) both parties take steps to build a consensus about the preferred treatment and (4) an agreement is reached on the treatment to implement. Focusing on the first two of the four characteristics of the model, we use the findings from a study of 62 consultations, together with interviews conducted with patients and general practitioners, to consider participation in the consultation in terms of sharing information about, and views of, medicines. We found little evidence that doctors and patients both participate in the consultation in this way. As a consequence there was no basis upon which to build a consensus about the preferred treatment and reach an agreement on which treatment to implement. Thus even the first two of the four conditions said to be necessary for shared decision making were not generally present in the consultations we studied. These findings were presented in feedback sessions with participating GPs, who identified a number of barriers to shared decision making, as well as expressing an interest in developing strategies to overcome these barriers.