Two studies examined the relationships between violence exposure, posttraumatic stress symptomatology, and delinquent activity among urban adolescents. It was hypothesized that adolescents that displayed higher levels of delinquent activity would retrospectively report higher levels of violence exposure, both within their families and in their communities, as well as higher levels of associated post-traumatic stress symptomatology. Study 1 involved a comparison between youth with significant levels of juvenile justice system involvement and a community sample of high school students that reported little to no involvement in delinquent activity. Study 2 examined differences within the sample of incarcerated youth and the relationship between more serious engagement in delinquent activity and higher levels of self-reported victimization and violence exposure. Data were obtained on a sample of 200 incarcerated youth and a matched sample of 200 high school students residing in similar inner-city communities. Study 1 revealed significant differences between incarcerated youth and the high school comparison sample. The prevalence of violence exposure and PTSD symptomatology among incarcerated adolescents was striking in comparison with high school students. The clearest difference that emerged was that adolescents that had come to the attention of the juvenile justice system were exposed to significantly higher levels of sexual violence and incidents of violence in their communities, such as physical assault and witnessing a homicide. Levels of PTSD were significantly higher than among high school counterparts. Study 2 results were more ambiguous. Within the incarcerated group, youth with more violence exposure reported higher levels of PTSD symptomatology. Differences in levels of delinquent activity were not consistently associated with higher levels of violence exposure. 3 notes, 2 notes, 25 references