OBJECTIVES: Comparison of providers' outcomes is intended to encourage patient choice and stimulate clinicians to improve the quality of their services. Given that success will depend on how patients and clinicians respond, our aim was to explore their views of using outcome data to compare providers. METHOD: Qualitative data from six focus groups with patients (n = 45) and seven meetings with surgical clinicians (n = 107) were collected during autumn 2010. Discussions audio-taped, transcribed and a thematic analysis carried out. RESULTS: Patients and clinicians confirmed the value of making comparisons of the outcomes of providers publicly available. However, both groups harboured three principal concerns: the validity of the data; fears that the data would be misinterpreted by the media, politicians and commissioners, and the focus should not just be on providers but also on the performance of individual surgeons. In addition, patients felt that information on providers' outcomes would only ever have a limited impact on their choice because there were other important factors to be taken into account: accessibility, waiting time, the size of the provider and the quality of other aspects such as cleanliness and nursing. Also patients acknowledged the importance of friends' and relatives' experiences and that they would seek their GP's advice. CONCLUSIONS: While comparisons of providers' outcomes should be available to patients to stimulate improvements in performance, information should be directed principally to hospital clinicians and to GPs. Impact may be enhanced by providing data on individual clinicians rather than providers. The extent to which these findings are generalizable to other areas of health care is uncertain.