Authors reviewed 28 cases of displaced acetabular fracture treated operatively from Februay 1991 to January 1996 and followed up more than 1 year. The clinical results were retrospectively analyzed with consideration of surgical problems and complications. The results were as follows; 1. According to Letournels classification, we had 16 elementary fractures(57%) and 12 associated fractures(43%). 2. Kocher-Langenbeck approach in 16 cases, ilioinguinal in 9 cases, extended iliofemoral 2 cases and combined approach in 1 case were used. 3. The devices for internal fixation were as follows: screw only in 12 cases(elementary fracture 9cases, associated fracture 3 cases), plate and screw in 16 cases(elementary fracture 7 cases, as-sociated fracture 9 cases). 4. There were complications such as 3 degenerative arthritis, 2 superficial wound infection, 1 iatrog-enic sciatic nerve palsy and 1 avascular necrosis of femoral head and no postoperative heterotro-phic ossification. 5. Satisfactory reduction by radiologic criteria was gained in 23 cases(82%). Satisfactory results by clinical criteria(by dAubigne & Postels) was gained in 21 cases(75%). Only 2 patient with a satisfactory radiologic reduction was clinically unsatisfactory. It seems that the satisfactory operative reduction of the fracture is the factor that correlates best with a satisfact-ory clinical result.