Public debt and its development are key questions of public sector economics and fiscal policy. This paper uses the Synthetic Control Method to study how different large-scale steps of European integration and the establishment of the EU fiscal framework have affected government debt in EU Member States. The results point to a notable debt-restricting effect of EU membership and the introduction of the Stability and Growth Pact for a large majority of the studied country groupings as well as for individual countries. Outside of a few individual countries, the actual government debt levels are substantially lower than in the synthetic alternatives.