This article analyses development of the Permanent Representation of the Czech Republic to the European Union (PermRep) from 2004, when the Czech Republic joined the European Union, until 2013. Its main aim is to test four concepts related to the three neoinstitutionalist theories – firstly, the path dependency and critical junctures models related to the historical neo-institutionalism, secondly principal-agent relation typical for the rational neo-institutionalism and the concept of the logic of appropriateness related to the sociological institutionalism. The authors try to determine which of these four models have the best explanatory potential when it comes to the development of the Czech PermRep. After analysing three independent variables (changes in executive, EU Council Presidency, EU strategies), and their impact on the dependent variable (character of the Czech PermRep), the authors conclude that particularly historical institutionalism and sociological institutionalism models have the greatest explanatory power while the contribution of rational institutionalism model of principal-agent is relatively weak.