The outcomes of total hip arthroplasty (THA) for the treatment of posttraumatic arthritis after acetabular fractures were inferior to those after primary non-traumatic THA.This study was performed in academic level I trauma center. From January 2011 to December 2014, a consecutive series of 21 patients (9 females), with average age of 56.7 years (range 29-75 years) who had posttraumatic hip joint arthritis after acetabular fractures, were included in our study. All patients underwent cementless THA. The average duration of follow-up was 26 months (range 24-36 months).At the latest follow-up, all patients could walk independently, thirteen (62%) patients had excellent Harris hip score, five (24%) had good HHS, and 3 (14%) had fair score. WOMAC scale decreased from 63 (range 42-92) to 4 (range 0-19). Two patients (9.5%) had heterotopic bone formation which did not affect the activity of the patients. There were no signs of loosening of the acetabular cups or around the femoral stem.Cementless THA is an ideal treatment for posttraumatic hip arthritis with anatomic restoration of the hip center to improve the functional results and decrease the incidence of complications and revision rate.