A well-documented finding in developmental psychopathology research is that different informants often provide discrepant ratings of a youth's internalizing and externalizing problems. The current study examines youth- and parent-based moderators (i.e., youth age, gender, and IQ; type of psychopathology; offense category; psychopathic traits; parental education, income, and stress) of informant discrepancies in a sample of young offenders and compares the utility of youth and caregiver reports against relevant clinical outcomes. Results indicate that gender moderated the discrepancy between informant reports of somatic complaints, while parenting stress moderated the discrepancies across reports of internalizing and externalizing psychopathology. Variables unique to the forensic context (e.g., offense category) were found to moderate cross-informant discrepancies in reports of internalizing and externalizing psychopathology. Further, youth self-reports of internalizing symptoms predicted a clinician-generated diagnosis of a mood disorder, while caregiver reports of aggressive behaviors predicted the presence of an externalizing diagnosis. Results highlight the importance of assessing informant agreement in the context of forensic assessment and raise questions surrounding the optimal use of informant data in this setting. (Contains 1 figure and 7 tables.)