The publication offers an overview of special investigative actions, their classification, and application standards. It points out the possibilities and importance of these investigative techniques for conducting financial investigations from a very practical point of view. Furthermore, through the analysis of national legal frameworks and the practice of applying special investigative actions in financial investigations, an effort was made to indicate the utility value of such obtained information and evidence, and therefore, an overview of selected court practice was also presented. It is particularly significant that an overview of some of the most important decisions of the European Court of Human Rights in the field of special investigative actions and national constitutional courts is presented to identify relevant standards that serve as a guide to competent judicial institutions.