Constitutional identity has recently emerged as a relevant concept in the theory of constitutional law. It first appeared in constitutional decision reasoning in the second half of the 20th century, particularly in cases concerning the process of European integration. Constitutional courts all over Europe have started to use this notion as a legal counter-argument against the growing influence of the European Court of Justice on the national legal systems of member states. At the theoretical level, the use of this new concept caused a lot of criticism by law scholars, due, in their opinion, to its non-legal unscientific character. At the same time, there are also many supporters of this concept, mainly the representatives of the civilizational and sociocultural approaches to law. One way or another, it is fair to say that this concept has captured the attention of constitutional lawyers who, nevertheless, have not come yet to a common understanding of this notion. Some of them suggest defining constitutional identity as a method of legal argumentation, but there are still no comprehensive studies of this concept using achievements of the theory of legal argumentation. This article represents an attempt to research the notion of “constitutional identity” through the prism of the latter. © 2019, Supporting Academic Initiatives Foundation. All rights reserved.