The institution of amicus curiae, commonly found in common law systems, has not yet reached a comprehensive analysis in Polish law. Despite the existing and slowly developing practice of bringing a court friend’s opinion within the Polish procedural rules, it is impossible to find expressis verbis regulations for the amicus curiae institution. This points to the need to undertake a scientific discourse on this subject, in particular its location among the applicable rules relating to the procedure before courts and tribunals. The study of the subject of the search for legal connotations aimed at reconstructing the characteristics of the amicus curiae is part of this study. The author’s intention is to define the position of a “friend of the court” in proceedings before the Constitutional Tribunal, the criteria for admission to the case and the determination of his or her legal position and the scope of entitlements.