Juvenile criminal law began to develop gradually, especially in the direction of recognizing the issue 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 pass 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 the general standards in the development of children and juveniles and the needs of each individual juvenile who finds himself in the criminal justice system. In 1997, the first Law on Juvenile Courts was passed, which took precedence over the provisions of the Criminal Code intended for adult offenders. No, with the accession of the Republic of Croatia to the European Union, the European legislation 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 the defendant in the criminal procedure. The process of harmonizing the rights of defendants in criminal proceedings also affected minors, and for this purpose, in accordance with the Guidelines for strengthening the procedural rights of suspects and defendants in criminal proceedings, Directive 2016/800 on procedural guarantees for children who are suspects or accused in criminal proceedings was adopted. All member states were obliged to implement it by June 11, 2019, and the Republic of Croatia implemented it with the latest amendments to the Law on Juvenile Courts.