Abstract
This study deals with the phenomenon of paradiplomacy, which desribes international activities of cities and regions. The first part of article is theoretical, including history of paradiplomacy and its causes.
The second part is a case study of foreign policy instituted by the City of Prague in the electoral term 2006–2010. This case study confirmed initial hypotheses: first, that paradiplomacy is influenced by three supra-national factors; second, that paradiplomacy is influenced by institutional and constitutional relations between the centre and regions; third, that paradiplomacy is influenced by the antagonistic nature of these relations.