Objectives: To report the technical aspects, radiographic results, and complications of a modified ilioinguinal approach for the treatment of bicolumnar acetabular fractures, especially involving the quadrilateral plate. Design: Retrospective review. Setting: Level I Trauma Center, Wuhan Union Hospital, China. Patients/Participants: Data from all acetabular fractures (n = 96) treated surgically were collected between January 2012 and June 2015. According to the exclusion criteria, 22 patients who had undergone a single supra-ilioinguinal approach with a minimum of 1-year follow-up were included in the study. Intervention: The supra-ilioinguinal approach was used to treat bicolumnar acetabular fractures by modifying the ilioinguinal approach, using the navel, anterior superior iliac spine, and the symphysis pubis as landmarks. Main Outcome measurements: The surgical exposure and reduction of fractures is expected to become more direct and convenient, with shorter surgical time, less blood loss, and fewer complications. Results: Of the 22 consecutive patients, 5 were anterior column with posterior hemi-transverse, 11 were associated both column, 3 were transverse and 3 were T-type patterns. Average length of incision, operative time, and intraoperative blood loss were 10.7 +/- 1.1 cm, 182 +/- 40 minutes, and 793 +/- 228 mL, respectively. Seventeen cases of the reductions were graded excellent; 4, good; and 1, poor. In the last follow-up, the Merle d 'Aubigne scores showed that 14 cases were excellent; 6, good; and 2, poor. Postoperative deep vein thrombosis occurred in 1 patient and lateral femoral cutaneous nerve injury in 3 patients. Conclusions: For the treatment of bicolumnar acetabular fractures, the supra-ilioinguinal approach provides direct visualization and convenient access to the quadrilateral plate, and allows for appropriate reduction and fixation with few complications.