PURPOSE: Fractures of the acetabulum remain a major challenge to the orthopedic surgeons. Although the operative treatment for the complex fractures is preferred, inaccurate reduction and then incongruity of the hip joint lead to serious complication such as premature osteoarthritis. We evaluated the results of surgical and conservative treatment for acetabular fractures. MATERIALS AND METHODS: From January 1996 to March 2001, we reviewed 55 cases retrospectively. Posterior wall fracture (13 cases) was the most common by Letournel's classification and followed by both column fracture (10 cases). Causes of injuries included 41 cases of traffic accident and 8 cases of falling down. We divided the cases into an operation group (28 cases) and conservative group (27 cases) and evaluated the results as excellent, good, fair or poor according to Matta's clinical and radiological grade criteria. RESULTS: Anatomical or satisfactory reduction was obtained in 22 cases of operative group and clinical results were excellent in 7 cases, good in 13 cases. Conservative group revealed excellent and good clinical results in 15 of 27 cases. CONCLUSION: In cases of the displaced complex fractures, posterior wall fracture with instability and displaced fractures involving the weight bearing dome of the acetabulum, open reduction and internal fixation after accurate evaluation of the fracture pattern could allow earlier ROM exercise and have the result in better prognosis.