We have exprierienced 10 cases of pelvic bone fractures that were treated by Hoffmann's external fixation devices from June, 1979 to June, 1982. As a result, following advantages were noted; 1. Rapid recuction of pain, prevention of serious early complication, and easiness of nursing care were possible. 2. Late complications such as lumbosacral pain and gait disturbance could be preventable in majority of the patients, as well as shortening the duration of the hospitalization.