The article is devoted to the issue of the dissenting opinion of a judge, which is relevant to modern law enforcement practice and legal theory and which may be expressed when a judge who participated in a collegial consideration of a case does not agree with the position of the majority of the panel of judges. The authors analyse the existing approaches to the institution of dissenting opinions in different legal systems, the factors that negatively affect the existence of dissenting opinions in the justice system, provide examples of dissenting opinions of Ukrainian judges expressed in different jurisdictions, their significance for law enforcement practice and the public outcry they caused. It addresses the procedural issues that may potentially arise during the judicial proceedings and the formation of a dissenting opinion of a judge. The authors conclude that the institution of dissenting opinion is of undoubted value for justice and the authority of the court in the State and emphasise that the specifics of the text of a judge's dissenting opinion against the background of lapidary normative regulation by the rules of procedural law may indicate the genre independence of the content of a dissenting opinion in judicial discourse as compared to a court decision. The authors propose the concept of dissenting opinion, by which they mean an official legal position of a judge which is formed during collegial consideration of a case as a result of an internal conviction which does not coincide (partially does not coincide) with the position of the majority of judges in terms of reasoning or final conclusion, and which is formalised in a procedural document which is an act of competent (professional) and doctrinal judicial casual interpretation. In addition, the authors present synthesised features which characterise a judge's legal opinion as a dissenting opinion, including the statement that it is undoubtedly a phenomenon of a democratic society; it has the features of an institution of law, albeit with lapidary normative regulation; it is issued by a judge within his/her competence as a result of judicial discretion and inner conviction; has a prognostic and forward-looking character, since it sometimes serves as a means of overcoming outdated views that impede progressive legal development, evolution of sustainable approaches, and as a basis for the formation of a new legal position, which in the future may be transformed into a majority position and become a sustainable practice; besides, it is derivative, optional, as it is not binding, unlike a court decision, and is not an act of justice, as it is not issued in the name of the state and is not a mandatory part of a court decision.