PurposeThe purpose of this study was to identify and analyze research into accreditation and accreditation processes.Data sourcesA multi-method, systematic review of the accreditation literature was conducted from March to May 2007. The search identified articles researching accreditation. Discussion or commentary pieces were excluded.Study selectionFrom the initial identification of over 3000 abstracts, 66 studies that met the search criteria by empirically examining accreditation were selected.Data extraction and results of data synthesisThe 66 studies were retrieved and analyzed. The results, examining the impact or effectiveness of accreditation, were classified into 10 categories: professions' attitudes to accreditation, promote change, organizational impact, financial impact, quality measures, program assessment, consumer views or patient satisfaction, public disclosure, professional development and surveyor issues.ResultsThe analysis reveals a complex picture. In two categories consistent findings were recorded: promote change and professional development. Inconsistent findings were identified in five categories: professions' attitudes to accreditation, organizational impact, financial impact, quality measures and program assessment. The remaining three categories—consumer views or patient satisfaction, public disclosure and surveyor issues—did not have sufficient studies to draw any conclusion. The search identified a number of national health care accreditation organizations engaged in research activities.ConclusionThe health care accreditation industry appears to be purposefully moving towards constructing the evidence to ground our understanding of accreditation.