Indicator system development for evaluating the quality of health services. The National Health Insurance Fund of Hungary introduces indicators for evaluating the quality of health services. The new system starts by the end of 2003 on the Internet and it will be updated and improved on a regular base. The quality indicators provide possibility to compare the health services and follow up the changes. The Hungarian indicators came from those indicators, which are described, tested and used in the international literature and practice. The data derive from the routinely collected financial data of the National Health Insurance Fund. The conclusions drawn form the results will be arranged and interpreted according to the types of indicators. Those providers whose have out of the ordinary values should fill in a standardized questionnaire--which was developed with the representatives of the certain profession--for explaining the results and define quality improvement plan. The aim of the programme is to increase transparency of health services, to enhance quality improvement and to support the certification and accreditation programmes.