Background. Acetabular fractures occur as a result of high-velocity trauma and are often associated with other life threatening injuries. Approximately one-third of these fractures are associated with dislocation of the femoral head but there are only few studies documenting the long term outcomes of this group of acetabular fracture. Methods. This was undertaken at the Royal Infirmary of Edinburgh which provides the definitive orthopaedic treatment for all major trauma including all acetabular fractures for the South East of Scotland. We retrospectively reviewed patients who sustained an acetabular fracture associated with a posterior hip dislocation from a prospectively gathered trauma database between 1990 to 2010. Patient characteristics, complications and the requirement for further surgery were recorded. Patient outcomes were measured using the Oxford Hip score and Short Form SF-12 health survey. Results. A total of 99 patients were treated over a 24 year period. The mean age was 41.3 years. The majority were male (75%). Road traffic accidents were the most common mechanism of injury (47%). The most common Letournal & Judet classification was a posterior wall fracture. Complications such as Sciatic Nerve Palsy was 12.1%, DVT 3%, Infection 5%, Heterotopic ossification 6.1%, Avascular necrosis at 11.1% and 19.2% went on to have a total hip replacement. The mean Oxford Score for Native hip was 34.7 and 31.8 for those who converted to hip replacement. SF12 Physical score was was 40.3 and 39 for the native hips and converted hips respectively. And the SF12 Mental score was 45.5 and 44.9 for the native hips and converted hips respectively. Conclusions. This is the first study to present the long term outcomes following an acetabular fracture dislocation. Our study suggests there is considerable disability in this group of patients and the requirement for subsequent THR has inferior patient reported outcomes. Level of Evidence. Cohort study, Level 2B