There is now extensive evidence demonstrating that there is a gap between the health care that patients receive and the practice that is recommended. In both primary and secondary care there are unwarranted variations in practice and in resulting outcomes that cannot be explained by the characteristics of patients.While it is difficult to find examples of measures for addressing this issue from all 53 countries of the World Health Organization's European Region, there are interventions that can be identified in the 27 Member States of the European Union. However, the nature of these measures and the extent to which they are implemented vary considerably.Audit and feedback defined as 'any summary of clinical performance of health care over a specified period of time aimed at providing information to health professionals to allow them to assess and adjust their performance' is an overarching term used to describe some of the measures that are used to improve professional practice.Audit and feedback can be used in all health care settings, involving all health professionals, either as individual professions or in multiprofessional teams.In practical terms, health professionals can receive feedback on their performance based on data derived from their routine practice. Health professionals involved in audit and feedback may work either in a team or individually and in primary, secondary or tertiary care.While it seems intuitive that health care professionals would be prompted to modify their clinical practice if receiving feedback that it was inconsistent with that of their peers or accepted guidelines, this is in fact not always the case.The available evidence suggests that audit and feedback may be effective in improving professional practice but that the effects are generally small to moderate. Nonetheless, depending on the context, such small effects, particularly if shown to be cost-effective, may still be regarded as worthwhile.The benefits of audit and feedback measures are most likely to occur where existing practice is furthest away from what is desired, and when feedback is more intensive.Even on the basis of the best evidence available, no strong recommendations can be given regarding the best way to introduce audit and feedback into routine practice. However, decisions about if, and how, this approach can Policy summary be used to improve professional practice must be guided by pragmatism and the consideration of local circumstances. The following scenarios, for example, might indicate suitability for such an approach: the known (or anticipated) level of initial adherence to guidelines or desired practice is low; it is feasible to conduct an audit and the associated costs of collecting the data are low; routinely collected data are reliable and appropriate for use in an audit; and small to moderate improvements in quality would be worthwhile.The cost of audit and feedback is highly variable and is determined by local conditions, including the availability of reliable routinely collected data and personnel costs.The impact of audit and feedback, with or without additional interventions, should be monitored routinely by auditing practice after the intervention.