Experience in operative treatment of severe unstable fracture of pelvic ring is presented. There were 91 patients with polytrauma. Biomechanical characteristics of pelvic bones and joints of different injury severity was given. Priorities of main diagnostic and curative management were defined in patients with concomitant pelvic injury. Efficacy of AO type external fixation device for the pelvic fracture stabilization in acute period was shown. In pubic symphisis rupture with diastasis over 3 sm. the method of internal fixation by modified plate was used. In old fractures osteosynthesis with alloplasty was carried out. In 79 patients follow up ranged from 1 to 10 years. Good results were achieved in 62 patients (78.5%), satisfactory results in 11 patients (13.9%)).