INTRODUCTION: In 2004 the Danish National Board of Health (DNBH) published new guidelines for the prenatal risk assessment and diagnostic service. The new guidelines are nationally implemented. DNBH has pointed out the importance of quality control, but has not given any specific guidelines concerning this. We demonstrate the feasibility of a quality assessment of a considerable part of the screening programme. MATERIALS AND METHODS: The quality assessment is conducted on a cohort from Holbaek Hospital during 12 months by merging data from one local hospital database to data from the Danish Cytogenetic Centralregistry and the Danish National Newborn Screening Registry. RESULTS: The study included 1796 singleton pregnancies and 47 twin pregnancies. 46 invasive procedures were carried out among the singleton pregnancies, which corresponds to an invasive rate of 2.6%. Two fetuses with Down's syndrome (DS) and one with trisomy 18 were found and the pregnancies were terminated. One fetus with Turners syndrome was diagnosed prenatally, but ended as a missed abortion. One child with DS was not diagnosed prenatally. The detection rate for DS was 2/3 (67%). CONCLUSION: We suggest that the outlined quality program is implemented as a national programme.