The first use of medical practice profiles in the Belgian healthcare organization goes back to 1980 with the creation of practice pattern evaluation at the National Institute of Health and Invalidity Insurance (RIZIV). Since then, detailed information on the provision and on the utilization of healthcare has become increasingly important in the planning, budgeting and financing of the nation healthcare. The RIZIV uses practice profiling predominantly as a means to control aberrant prescription (e.g. clinical chemistry, medical imaging, pharmaceuticals) and provision of care (diagnostic tests). In 1991, the Federal Ministry of Health started using data on diagnosis and medical performance for hospital admissions in order to adapt the per diem price and the yearly quotum of admission days attributed to each hospital. At the level of the health insurer (sickness funds) there is growing interest to share the information derived from the extremely detailed patient claims for reimbursement of intramural and ambulatory care. These billing data allow the evaluation of medical care provision per physician, per hospital or provision center and per patient for a given period of time. The lack of specific diagnosis indication restricts mainly the use of these data as medical performance parameter to surgical procedures. The purpose of this profile information for the health insurer is to point to the physician the important medical practice variability in identical clinical situations in order to stimulate the design and implementation of practice guidelines and reduce aberrant differences in practice patterns. The use of medical practice profiles, in close collaboration of insurers and providers is considered extremely valuable as a means to improve the quality of healthcare provision.