We report a case of traumatic dislocation of the hip in a child.A three-year-old boy fell down, and his right knee was hit on the ground. Just after the accident, he could not move his right leg because of severe pain in his right hip. When he came to our hospital, he kept his right hip in a flexion, internal rotation and adduction position. A hard mass was palpable in the right gluteal region. The X-ray findings showed right hip posterior dislocation without fracture and no congenital skeletal dysplasia of the hip was seen. Four hours after his injury, he received closed reduction under general anesthesia, followed by skin traction in the abduction position of his right hip.Ten days after reduction, MRI and CT showed that there was no fracture and cartilage damage. He felt no hip pain and started to walk on full weight bearing.Nine months after the incident, MRI showed no significant abnormal findings such as bone necrosis and dysplasia of the hip, and the patient had no complaints of problems in daily life.