Assessed the amount and severity of exposure to crime and violence in an urban sample of high school students, determined the extent and nature of consequent posttraumatic stress disorder (PTSD) symptoms, and examined moderating effects of social support and coping style on those symptoms. 96 students (aged 14–18 yrs) were assessed using the Survey of Exposure to Community Violence, the Analysis of Social Support in School Transitions, and the Posttraumatic Stress Disorder Reaction Index. More than 93% of Ss reported having witnessed a violent event, and 44% reported having been a victim. The average number of PTSD symptoms reported by Ss exposed to a traumatic event was 10, and 34.5% of Ss met full Diagnostic and Statistical Manual of Mental Disorders-III-Revised (DSM-III-R) criteria for PTSD. Results are consistent with earlier findings (K. Kaniasty and F. Norris; see record 1992-39580-001) that perceived social support is a more effective predictor of positive outcome than social support actually received. (PsycINFO Database Record (c) 2013 APA, all rights reserved)