One hundred fifty-nine children (14.5% of the student body) were sampled after a fatal sniper attack on their elementary school playground. Systematic self-reports of posttraumatic stress disorder (PTSD) symptoms were obtained by use of a child PTSD Reaction Index. Analysis of variance revealed significant differences by exposure but not by sex, ethnicity, or age. Additional analyses were conducted of individual item response, overall severity of PTSD reaction, symptom grouping, and previous life events. The results provide strong evidence that acute PTSD symptoms occur in school-age children with a notable correlation between proximity to the violence and type and number of PTSD symptoms. Sampling at approximately one month after the trauma provided adequate delineation among exposure groups. The symptom profile of highly exposed children lends validity to the diagnosis of acute PTSD in childhood.