The Danish Epidemiology Science Centre under ‘Statens Serum Institut ( SSI)’ was founded in 1994 by a substantial grant from the Danish National Research Foundation. Among the objectives of the centre was a wish to combine the financial, technical and human epidemiologic resources in Denmark in order to be able to undertake epidemiological investigations of a magnitude that could normally not be done in smaller units. The largest, and most ambitious, project initiated by the Danish Epidemiology Science Centre is the Danish National Birth Cohort, which has recruited 100,000 pregnant women for long-term follow up of themselves and their subsequent children. The main centre of The Danish Epidemiology Science Centre is situated at Statens Serum Institut, Copenhagen. Three subcentres are situated at Institute of Epidemiology & Social Medicine, University of Aarhus; Department of Epidemiological Research, Statens Serum Institut, Copenhagen; and Institute of Preventive Medicine, University of Copenhagen. A total of about 50 researchers are currently employed at, or otherwise formally affiliated to the Danish Epidemiology Science Centre.