Clinical laboratories in Belgium working within the social security system require to be licensed. Internal quality control and participation in external quality assessment (EQA) belong to the licensing conditions. The evolution of the Belgian EQAs is outlined, including a performance evolution over the last ten years. Halving of interlaboratory CVs is observed for most clinical chemistry and immunoassay analytes. Improvement is less spectacular for haematological analytes and is missing for coagulation analytes. Using the results of EQAs 1989-1991 the mean overall method interlaboratory CVs could be estimated. Using data from a commercial internal quality control program for clinical chemistry and a request in 145 laboratories, current intralaboratory CVs are estimated