There is some debate about whether sex offenders are similar to non-sex offenders. It is known that sex and non-sex offenders are heterogeneous groups. Comparative studies must take this heterogeneity into account. Based on an aggregated database, a study was conducted among adjudicated juvenile (sex) offenders. The sample consisted of juvenile male sex and non-sex offenders who had been subjected to a psychological assessment at the request of the judge or district attorney. The central question focused on the differences between juvenile sex offenders, in particular rapists and sexual assaulters (n = 57), child molesters (n = 55), and non-sex offenders: violent (n = 85) and nonviolent offenders (n = 80). The results demonstrated that sex offenders differ from non-sex offenders with regard to demographic characteristics, problem behavior, and personality traits. Some reference is made regarding future research.