The subject matter of this paper is the different conceptions of juvenile delinquency. This issue is particularly important when it comes to the socially unacceptable phenomena, such as juvenile delinquency and juvenile crime. This paper is not aimed at advocating for the specific use of one or the other legal term in the process of defining the illicit behaviour of juvenile offenders. The authors underscore that the proper application of these legal terms largely depends on the scope and extent of illicit conduct that the specific term entails and conceptually defines. Different conceptions of juvenile delinquency will be presented both in Serbian and foreign available criminological literature.