RESUMO
We describe an unusual case of delayed retropneumoperitoneum caused by a deep vaginal laceration as a result trauma from a water jet in a fountain. A 7-year-old premenarcheal girl presented to the emergency department after experiencing an injury from a water jet at a fountain park. Initially, the patient's vital sign and perineum were within normal range. Because the patient's vital signs became unstable 12 hours after vaginal injury, we carried out abdomino-pelvic computed tomography resulting in retropneumoperitoneum. Arterial bleeding from vaginal lateral wall was founded and controlled by electrocoagulation. No damage to the rectum was laparoscopically confirmed. A diagnostic laparoscopy, not laparotomy, should be considered in cases of retropneumoperitoneum with an ambiguous cause first.