A study was made of post-traumatic stress disorder in 200 children aged 7–11 years who had witnessed a public hanging next to their school in Isfahan, Islamic Republic of Iran. A standard checklist was completed through interviews with the children’s parents 3 months after the event. Post-traumatic stress disorder symptoms were identified in 104 children (52%), with 88 suffering re-experiences, 24 avoidance and 62 hyperarousal. The mean stress severity according to the Child Post-Traumatic Stress Reaction Index was 39.1, indicating a moderate to severe severity of stress. The study highlights the serious emotional effects on children who witness traumatic events.