A retrospective study of 46 posterior fracture-dislocations of the hip showed that reduction of the dislocation within 24 hours was the most important initial treatment. Open reduction and fixation of the fracture could be delayed up to 4 weeks to allow associated injuries to be treated, and this technique was indicated to remove intra-articular bone fragments or for residual instability. Long-term disability resulted in every patient, regardless of the severity of the initial injury or the method of treatment. Half of the patients never returned to work. Of the 46 patients 43 were unrestrained occupants in vehicular accidents. Multiple injury occurred in 75% of the patients.