At present the topic "quality of health care" takes up a central position in the Danish debate, both among health professionals and politicians. In the present review the terms quality, quality assessment, and quality assurance are attempted defined and described. To assess the quality of health care deliveries it is necessary to establish indicators, criteria and standards. Indicators are defined variables which reflect deviations in quality. Criteria are established determinants of the optimal level of care while standards represent the degree of fulfillment of these. The relationship between indicators, criteria, and standards are illustrated. Quality assurance is a continuous process based on identifying quality problems for a given health delivery, and determining criteria and standards in relation to this. Quality assessment is the data collection and analysis through which the degree of conformity to predetermined standards and criteria are exemplified. If the quality, through this process is found to be unsatisfactory, attempts are made to discover the reason for this. On the basis of this, remedial actions are instituted and the quality reevaluated after a suitable time period. This stepwise process makes quality assurance a dynamic activity where criteria and standards are revised continuously with the overall purpose of improving the quality of health care services. Quality assessment and assurance should be incorporated as routine activities for health professionals. However, development, testing, and validation of the tools and methodologies for this new discipline are research activities.