Research was undertaken on the criminal careers of a large group of juvenile sexual and non-sexual offenders (of violence and property) in the Netherlands. Data from police records over a 6-year period from 1996 to 2002 were analysed. Results show that, with the exception of those in the exhibitionist subgroup, young sexual offenders start their criminal careers at an earlier stage than their non-sexual counterparts. Each of three subgroups of adolescent sexual offenders showed important and interesting variations in offence registrations. The majority of the young sexual offenders studied went on to recidivate sexually but were observed more commonly to "cross over" to property offences. However, a small proportion of adolescent sexual offenders continued their sexual offences over time and were in need of specialist professional intervention. Limitations of the study are discussed and implications of the findings for management and treatment explored. (Contains 1 table and 5 figures.)