Direct democracy exhibits both promise and peril for the EU. The referendum has been deployed by Member States in a way that has shaped and will continue to shape the EU’s geographical boundaries, its constitutional evolution, and salient EU policy matters. The referendum’s promise is to accord a high degree of legitimacy to a political decision, but that promise varies across different types of EU referendum. Their peril for the EU has become increasingly apparent as they have proliferated in number and type and with a growing failure rate. In contrast, the European Citizens’ Initiative is intended to harness the promise of direct democracy for the EU. But current practice raises the question of whether the failure to satisfy the ambitions placed on this novel instrument could, paradoxically, become a source of peril. Contrary to an increasingly pessimistic narrative, it is concluded that practice under the ECI exhibits promise and that the future of this instruments appears bright.