The article asks whether the European Union (EU)’s duty to protect national identities is a useful way to address diverging conceptions of fundamental rights, and it argues that it is not. On the basis of an examination of the text of Article 4(2) TEU, its history and the practice of the Court of Justice, it is argued that the concept of ‘national identities’ under Article 4(2) TEU does not cover particular national conceptions of fundamental rights, but admits that it may be difficult to make a clear separation between the more organizational or structural elements of national identity and their impact on the fundamental rights of individuals. The article then proceeds to look at national approaches, where fundamental rights tend to be included in the concept of constitutional identities to be protected by national courts. It is argued, however, that arguments based on constitutional identity under national law are not conducive for deciding cases on EU fundamental rights. Such identity claims operate as trump cards. Yet, there are other ways to accommodate diversity among the Member States in the area of fundamental rights. If these are used and respected also by the Court of Justice, unilateral recourse to constitutional identity is not needed.