Federalism and referendums refer to important policy decisions in different societies, but so far, they have been analysed separately. This article addresses the gap in the literature and focuses on the relationship between federalism and the use of referendums. It aims to show how the federal or unitary systems could influence the use of referendums at national level. The analysis compares six countries in the European Union – Austria, Belgium, France, Germany, Ireland and Romania – out of which three are federal and three are unitary. The data comes from secondary sources that include databases on direct democracy, country reports, or websites of central governments. The study covers the most recent two decades. The main findings show a limited effect of federalism on the use of referendums but provides several important nuances that can be used by further research.