The rise of regional administrative courts is one of the most important recent evolutions with regard to the organization of justice in Belgium. The decisions of Flemish administrative judges have a big impact on people’s lives, ranging from disputes about environmental permits to even election results. However, the creation and organization of these courts raises crucial questions connected to the rule of law. Incorporating the administrative judicial apparatus or its supporting units within the executive branch touches upon the separation of powers and judicial independence. Moreover, aspects of the right to a fair trial are at stake, for example when cases are decided by single judge panels and no possibility for a full appeal is available. The Flemish government envisions the further development of the administrative judicial system. Fundamental research into those matters is needed now. Surprisingly, at this moment that is nearly completely lacking. Supported by comparative law and a participatory methodology, this project answers theoretical, empirical and normative questions. It offers a path to develop administrative judiciaries in the Belgian federated entities in line with the rule of law. Furthermore, it provides an new perspective on dualistic judicial systems and contributes to the (equally limited) international literature concerning administrative court organization.