This prospective study assessed the reliability and validity of the Inventory of Callous-Unemotional Traits (ICU) in a sample of 70 adolescent offenders. With the exception of the Unemotional subscale, ICU scores showed acceptable reliability. ICU total and Callousness scores demonstrated moderate associations with the Antisocial Process Screening Device and the Psychopathy Checklist: Youth Version. The ICU also demonstrated moderate predictive accuracy for violent reoffending over an 18-month follow-up period. While these findings provide some support for the ICU’s validity, more research is needed to determine if it is appropriate for use in applied settings with adolescent offenders.