Originally written as a background paper for the discussion on the research needs in quality assurance by the WHO's global Advisory Committee on Health Research, this paper has two sections. The main section introduces key political, organizational and methodological issues. Special attention is being paid to unsolved problems and controversies to whose resolution research could contribute. The main issues and research needs relate to the concept of quality; conflicting expectations and objectives of the concerned parties; the need to broaden the scope of quality assurance from the science of medicine to art of medicine, from the process of care to the outcome of care, and from exclusively professional concerns to patient satisfaction; relationship between quality assurance and such related concepts as technology assessment and risk management; development of measurement methods; choice of proper subject of quality assurance; and setting criteria and standards of good quality. In addition, research into the epidemiology of quality, introduction and organization of quality assurance and correction of observed defects is needed. Quality assurance itself also needs to be evaluated.