In modern conditions, the study of the sources of constitutional law of foreign countries is extremely relevant. The scientific article determined that judicial precedent is the main source of constitutional law of the states of the Anglo-Saxon legal system and an auxiliary source of constitutional law in the Romano-Germanic legal system.
 The scientific article also focuses on the fact that on February 23, 2006, a fundamental Law was adopted in Ukraine – the Law of Ukraine «On the Implementation of Decisions and Application of the Practice of the European Court of Human Rights». It was determined that the adoption of the above-mentioned legislative act had at one time not only a theoretical significance for legal science, but primarily a practical significance for the functioning of the courts, since the requirement of this legislative act is the strict implementation of the decisions of the European Court of Human Rights, which in turn recognizes precedential law.
 The work also determined that earlier, court precedent in Ukraine was not a universally recognized source of constitutional law. However, over time, court precedent began to take on extremely important importance, and domestic courts increasingly operate with the practice of higher courts when making certain decisions. Therefore, the scientific article substantiates the importance of the study of judicial precedent as a source of constitutional law in foreign countries, since the relationship to this source of constitutional law in common law states and continental law states is fundamentally different.
 Also, in the scientific article, special attention is paid to issues related to the practice of applying judicial precedent in each of the modern legal systems. In particular, it is determined what influence the court precedent had on the development of constitutional law, whether courts act as subjects of judicial law-making or not, the main aspects of the court precedent and its relationship with judicial practice are determined.
 The scientific article also highlights how judicial precedent is applied in France, Germany, Great Britain, as well as specific features of its application in Ukraine.
 As a result, it was determined that judicial precedent is determined by law as a special source of constitutional law of foreign countries, and therefore for Ukraine it should also occupy a particularly important place in the system of sources of constitutional law, although at the same time it is inferior to the normative legal act as a fundamental source of constitutional law - the German legal system, which includes Ukraine.