Minority groups rely heavily on international judicial review when national systems fail to protect their rights. The European Court of Human Rights aspires to protect minority groups by providing a supranational level of review to which minorities can resort when their rights have been violated. But does the Court live up to its promise? Resort to the ‘margin of appreciation’ doctrine in analyzing minority rights casts serious doubt on the effectiveness of the Court’s review of cases with respect to these groups. This paper examines the Court’s case law relating to minority rights, focusing on how the margin of appreciation has been applied, in some ways, to the detriment of the very groups the Convention is meant to protect. It looks at recent shifts with respect to the application of this principle, and provides wider reflections on what these tendencies mean for the protection of minority rights in supranational institutions.