The study reported in this article examined the prevalence of eligibility for educational services for serious emotional disturbance (SED) among incarcerated youths, as well as how this designation relates to offender type. Administrative data from juvenile corrections, county child welfare agencies, and the state Department of Education (special education services for SED) were matched across systems and used to investigate the relationship of SED to violent offending among incarcerated adolescents while controlling for prior child welfare and juvenile court histories. Logistic regression was used to understand whether youths with SED designations were more likely to be incarcerated for violent offenses. SED status was not significantly associated with incarceration as a violent offender. Implications for screening and intervention services are discussed. Key words: juvenile corrections; serious emotional disturbance; special education; violence ********** Concern regarding the relationship between mental health disorders and serious and violent youthful offending is not new. Research indicates that comorbidity of psychiatric disorders and delinquency among youths is fairly substantial (Farrington et al., 1990; Loeber, Brinthaupt, & Green, 1990; Reinherz, Giaconia, Lefkowitz, Pakiz, & Frost, 1993; Williams, Ayers, & Arthur, 1997). Various studies have estimated that youths in juvenile justice systems experience mental health disorders at a rate of two to four times that of youths in the general population (Otto, Greenstein, Johnson, & Friedman, 1992). Yet, although the comorbidity research seems relatively well-developed, the study of how and when needs are identified and served is a newer area of inquiry (Burns, 1999; Stouthamer-Loeber, Loeber, & Thomas, 1992; Teplin, Abram, & McClelland, 1997). This gap in knowledge hampers the ability to guide policy and practice regarding when and how to intervene. Research on mental health services and serious delinquency is complicated by the fact that different agencies use different eligibility criteria for services. Although schools are major providers or brokers of mental health services for children (Zahner, Pawelkiewicz, DeFrancesco, & Adnopoz, 1992), studies of mental disorder among delinquents typically focus on diagnostic labels such as DSM-IV diagnoses used by noneducation personnel. Yet, some school-based mental health services, such as the educational services provided for serious emotional disturbance (SED), are based on entirely different criteria. For a youth to have a label of SED, he or she must exhibit one or more of the following to a marked degree so that it affects educational performance: the inability to learn that cannot be explained by intellectual, sensory, or health factors; an inability to build or maintain satisfactory interpersonal relationships with peers and teachers; inappropriate types of behavior or feelings under normal circumstances; a general pervasive mood of unhappiness or depression; and a tendency to develop physical symptoms or fears associated with personal or school problems (Office of Special Education Programs, 1997). The present study adds to the emerging body of research on service use, SED, and delinquency by investigating mental health disorder identified by the public school system among incarcerated juveniles. Estimates of the prevalence of SED among youths can be unreliable because of problems with definitions, measures, and methodology. The United States Office of Special Education Programs (1997) estimated that between 1 and 10 million children are disabled by SED, but only about 440,000 children are receiving special education services. Other researchers estimated the prevalence rate of SED for youths in the general population at 9 percent to 13 percent (Friedman, Katz-Levy, Manderscheid, & Sandheimer, 1996). The national rate of special education service for SED has remained stable at slightly less than 1 percent (Oswald & Coutinho, 1995). …