This diploma paper presents the special investigative techniques with regard to the reasons of enacting them by the legislator and wit the insight into human rights that are limited by applying them and the methods of their implementation. Considering the aforementioned, there are pointed out and clarified respectively, the principles underlying the application of special investigative techniques. Furthermore, this paper stipulates the time constraints and catalog a number of offenses for which special investigative actions can be applied, the participants in the decision-making process of the startup, application and control of special investigative techniques. Specifically, the court, prosecution and police with their roles. Special investigative techniques are relatively new in the Croatian criminal procedural law. With the aim of successfully challenging the new forms of contemporary crime, the legislator is forced to introduce new ways of fighting them, and that is what is known as the special investigative techniques. The specificity of the application of the process investigative techniques is that they are deeply penetrating into the personal rights and freedoms. The paper presents a conflict between the rights of the state in combating crime, and protection of human rights and freedoms. Undoubtedly, the legislator has given priority to the country in the fight against criminality. However, this advantage is strictly limited to the aim of preventing illegal acts in the form of judicial review of the implementation of special evidentiary actions, just in order to protect human rights and freedoms. Finally, by listing all of the special investigative techniques, they are all explained into details.