Most mediastinal abscesses result from infections after thoracotomy, esophageal perforation or penetrating chest trauma.This disease is rarely caused by closed blunt chest trauma.All previously reported such cases after closed blunt chest trauma presented with hematoma and stal osteomyelitis resulting from stal fracture.Here we report a 15-year-old sumo wrestler who presented with an anterior mediastinal abscess without any mediastinal fracture.The mediastinal abscess resulted from the hematogenous spread of Staphylococcus aureus to a hematoma that might have been caused by a closed blunt chest trauma incurred during sumo wrestling exercises.