The treatment of acetabular fracures remains controversial. Conservative treatment can be very successful provieded that congruency is achieved and maintained with traction. If congruency is not achieved, a poor prognosis may be expected and operative treatment is indicated. Open reduction and internal fixation has been proposed for all displaced acetabular fractures, asuming that late degenerative changes will be decreased by anatomical reduction of the articular surface. We analyzed 28 acetabular fractures treated by open reduction and internal fixation at Wonju Christian Hospital between February, 1984 and December 1990, with an average follow-up of 3.6 years(2 to 6).