The fiscal aspects of organizing a state are central for shaping state–citizen as well as center–region relationships. The quality of fiscal regimes and its acceptance among the different actors in federal and decentralized states can be crucial for ensuring the continuance of states. Debating Fiscal Federalism in Europe can no longer be limited to federal states. The phenomenon of strong federal elements in non-federal states especially materializes in the realm of fiscal affairs. Today Europe is witnessing in this very aspect one of the most important challenges to the model of the nation state. Leading European scholars examine the state of fiscal decentralization in selected European states and point out key challenges in the fiscal arrangement of center–region relations in Europe.