Juvenile criminal law began to develop gradually, especially in the direction of recognizing the problem of juvenile delinquency, which hides some specifics and a strong foundation for the further development of criminality. In order to suppress it, it became extremely important to adopt a series of provisions with a preventive, deterrent and educational effect aimed at helping and protecting young offenders. Taking into account the primary task of dealing with juvenile offenders, it was necessary to regulate the procedures for juveniles in a way that takes into account general standards in the development of children and juveniles, as well as the personality and needs of each individual juvenile who finds himself in the criminal justice system. As it was understood that it’s necessary to provide special rules that will regulate the criminal protection of children and juveniles, a reform in the Republic of Croatia resulted the adoption of the first Juvenile Courts Act in 1997, which, as lex specialis, took precedence over the provisions of the criminal law intended for adult offenders. However, by entering the Republic of Croatia into the European Union, European legislation greatly influenced the development of the criminal procedure with its instruments, especially directives, in the desire to achieve the greatest degree of harmonization, prescribing the individual rights of defendants in criminal proceedings. The process of harmonization defendant’s rights in criminal proceedings also affected minors, and for this purpose, in accordance with the Resolution on a Roadmap for strengthening the procedural rights of suspected or accused persons in criminal proceedings, the Directive (EU) 2016/800 on procedural safeguards for children who are suspects or accused persons in criminal proceedings, was adopted. All member States were obliged to transposed it by June 11, 2019., and the Republic of Croatia did that with the latest changes of Juvenile Courts Act.