If the treatment of acetabular fractures are not satisfactory, there will be serious complication such as traumatic arthritis or avascular necrosis of the femoral head. There is much continuing discussion as to where conservative or surgical treatment should be used. The authors experienced 41 cases of acetabular fractures, that wrere treated at the Department of Orthopaedic surgery, Maryknoll Hospital from January 1981 to September 1987. The results of 29 cases who were followed over a 1 year period are as follows:1. According to Letournel's classification, the most common type of elementray fracture was posterior wall(24.1%) and a T- shsped fracture was 10.3 % and both column fractures were 10.3%. 2. Complications were traumatic arthritis(14 cases), superficial infection(5 cases), ectopic ossification(5 cases), osteomyelitis(1 case), AVN of the femoral head(1 case), and iartrogenic femoral shaft fracture(1 case). 3. According to matta's assessment, satisfactory results of conservative treatment were 38% clinically and 38% radiologically, and by surgical treatment, 73% clinically and 64% radiologically. 4. Surgical treatment in acetabular fractures, such as an anatomical reduction and rigid fixation fixation followed by early joint motion were improved the result and decresed the rate of traumatic arthritis.