AIMS: The European Union (EU) enlargement of 2004 brings both opportunities and challenges for public health. It is believed that further integration will bring direct health benefits, mainly through improved socioeconomic conditions, but there are also risks associated with the EU expansion, in particular cross-border health risks, such as the impact of the internal EU market policy of free movement and migration on communicable disease patterns. Against this background, this article examines communicable disease policy development in Finland, Norway and Sweden in response to changing European political frontiers, in particular the EU accession of the Baltic States. The emphasis is on HIV/AIDS and tuberculosis. METHODS: The study is based on a qualitative and quantitative approach, using two complementary methods: documentary analysis and stakeholder analysis. RESULTS: The article identifies a distinct pattern in communicable disease policy development between 1990 and 2005. The turn of the new millennium saw a sharp increase in national attention and the priority assigned to communicable diseases in Finland, Norway and Sweden. The article argues that this development is likely to be related to the rising national, regional and European awareness of the public health challenges associated with communicable diseases in today's borderless Europe. It also shows that the Baltic health situation is a particular concern for Finland. CONCLUSIONS: Although there is increasing national and regional activity within the communicable disease area, there is a need for a more effective European approach to tackle the future communicable disease challenges that may follow in an increasingly interdependent and integrated Europe.