Abstract : With modern fracture management techniques, there is the possibility of anatomic acetabular fracture, the risk of post-traumatic arthritis, and the need for hip arthroplasty. few studies have evaluated outcomes of postponed total hip arthroplasty in acetabular fracture patients. So, the aim of this study was to evaluate the total hip arthroplasty in patients previously treated with internal fixation, to pay more attention to the details of this type of surgery and to minimize surgical complications. In this prospective study 20 patients with secondary degenerative joint disease (DJD) or avascular necrosis (AVN) following Internal Fixation surgery of Acetabular fracture, were enrolled. All subjects underwent a second surgery of Total Hip Arthroplasty during 2010-2013 in Imam Hossein Hospital. The patients were followed up every 6 months. Surgical outcome was measured on the basis of Harris criteria in addition to xray studies aimed to assess loosening and heterotopic ossification. 20 patients were involved in our study who had previously undergone surgery due to acetabular fracture. The mean age at the time of surgery was 28.3 ± 0.97 years. Vehicle accidents were the most common mechanism of injury in these patients and most patients suffered from Pos. Column fracture, on average after 0.25± 4.9 years’ patients became candidate for hip replacement surgery due to severe DJD. The patients were followed for a mean duration of 2.85 ± 0.22 years in which surgical complications occurred in two cases; infection was diagnosed in one while the other experienced hematoma. When evaluating the patients based on Harris criteria, most patients had an excellent outcome while a poor outcome was reported in none of the cases. According to our results, hip arthroplasty is an appropriate approach in the treatment of secondary DJD and AVN. It can even lead to optimal results in young patients