The paper presents the basic determinants that define the concept of juvenile and juvenile delinquency and the basic assumptions related to delinquent behavior of young people, which are defined by describing various factors that influence and contribute to the development of this phenomenon. Factors can be divided into groups of influences regardless of their root causes - genetic factors, psychological and behavioral, family, socialization factors and social factors, of which social and family factors undoubtedly dominate in their influences on the development of juvenile behavior. Furthermore, the differences between the legislations within different European countries with regard to juveniles are highlighted, the age limit for liability in terms of criminal law is analyzed, as well as the types of criminal sanctions that are imposed and applied to juveniles. In Croatian criminal law, the term juvenile is defined in Article 7 of the Criminal Code and the Family Law, the issue of juvenile delinquency is regulated in more detail by the provision of the Juvenile Courts Act. Criminal sanctions imposed on juvenile perpetrators of analysis are on the example of the Republic of Croatia, which covers the period from 2015 to 2019, based on collected and analyzed data on reported, accused and convicted juveniles with regard to the selected variable such as gender, age, the type of criminal offense and the criminal sanction imposed.