Determining the measure of pre-trial detention restricts the defendant of the fundamental right - freedom. The application of measures becomes even more complex when it is determined for juvenile offenders. Juvenile criminal law has adjusted the criminal procedure for juveniles so that it does not adversely affect their development and personality, but how did the application of the measure of pre-trial detention to young perpetrators fit into the above? In order to determine it, the paper will first explain how the restriction of individual freedom is justified due to the needs of criminal proceedings, furthermore, the legal regulation of the institute in the Croatian legal system will be presented. The second part of the paper deals with criminal proceedings and the application of pre-trial detention to juveniles. For this purpose, the international conventions, the case law of the European Court of Human Rights on the protection of juveniles deprived of their liberty and the harmonization of juvenile criminal law at the EU level will be reviewed. In conclusion, the criminal procedure regulation of the application of the measure of pre-trial detention to juveniles will be analyzed: the application of general and special provisions, more lenient alternatives envisaged by the legislator and how the execution of the measure is intended. On the other hand, it will be shown how the execution of the measure really works today through research on the application of pre-trial detention as a last resort, case law and reports of the competent authorities on whether the enforcement of the measure is carried out.