A meeting organized by Nederlands Tijdschrift voor Geneeskunde discussed the various interfaces of the quality of care, cost-effectiveness and health care. Cost-effectiveness analyses can contribute greatly to the quality of health care, but such research is methodologically complicated. Also, the effectiveness of particular interventions or therapies should be taken into account, if possible evidence-based, in the introduction of standards or guidelines for health-care workers. In practice, however, owing to various circumstances, the implementation of such guidelines leaves something to be desired.