In this article I explore the judicial dimension of federal systems from a subnational perspective. The findings show that regardles of the type of federalism subnational courts of last resort underscore plurality and diversity and thus inject federal ideas into the two systems. Federalism is, hence, not only an overall structure that shapes the judicial system but an intrisic part of judcial review. If we discuss constitutional adjudication and high courts in federal systems, we must take the subnational level into account. Without giving this level its due credit, we are unable to understand neither federalism in general nor judicial federalism in particular.