This article analyses the data on minors included in the police, prosecution, conviction, prison and probation statistics of 45 European nations in 2010, which were collected in the European Sourcebook of Crime and Criminal Justice Statistics. The main conclusions of the analysis are that comprehensive juvenile justice statistics are seldom available and that the existing data are hardly comparable across countries. The article identifies the main reasons that hamper the comparability: The definition of minors is not harmonized, the rules applied for the construction of the statistics are not the same, and there
are differences in the legal procedures foreseen for minors as well as on the type of sanctions that can be imposed to them. As a consequence, European juvenile justice statistics do not provide valid comparable information on the extent of juvenile delinquency, and their reliability as indicators of the social reaction to it is doubtful.