Characteristics of chronically violent or aggressive youth typically include hostility, impulsivity, substance abuse, major mental disorders, antisocial personality/psychopathy, social information-processing deficits, experience of poor parenting, and neglect as a child. These factors can be organized into domains and compared among different types of violent offenders to demonstrate the need for matching offenders' treatment needs with program content. These five domains can be related to the expression or inhibition of violent behavior: (1) competence (social skills and empathy); (2) arousal (anger); (3) schema (aggressive beliefs and hostile attributions); (4) self-regulation (impulsivity); and (5) anxiety (neuroticism). The article discusses treatment intensity, residential versus community-based programs, treatment programs, pharmacological interventions, psychological interventions, program effectiveness, and future directions. Notes