This paper presents a quantification of the economic impacts to Denmark of the European Unions’ upcoming East enlargement. Specifically the effects of customs liberalization, market integration and immigration are quantified with due regard to estimated repercussions to transfers to and from the European Union and enhanced growth in the new member states. In the basecase projection, which excludes additional immigration, a steady state increase of aggregate GDP at factor costs of 0.08 percent is found along with a welfare gain of 1.27 percent of 1998 GDP. The welfare gains are demonstrated to be highly dependent on the catching up of the CEE region and the route taken by the EU for funding the enlargement.