While increased attention has focused on explaining and intervening in young criminality, scant research in Europe and North America has focused on evaluating criminal justice interventions that target children and juveniles. The current study presents findings from the Persistent Young Offender Project in the United Kingdom that offers an innovative offending behavior program for persistent young offenders, roughly half of whom are aged 12 years or younger. Participants for the evaluation were 41 juveniles between the ages of 7 and 16 years who had been enrolled in the program for more than 6 months and had been assessed at least twice. The evaluation relied on measuring criminogenic risks and needs of the intervention group and a non-intervention group of juvenile offenders at 6-month intervals using the Level of Service Inventory-Revised (LSI-R). Local police data were also analyzed for both groups as an indicator of criminal behavior. Results indicated that the intervention group experienced a significant decrease in LSI-R scores, with the effect sizes improving dramatically with longer-term intervention. Results also suggested that actual offending rates among the intervention group dropped as well. The comparison group experienced no such drop in criminogenic risks, needs, or offending rates. Future research should continue to provide empirical evidence on programming that works to reduce juvenile offending. Footnotes, figures, table, references