From 1980 to 1987, 136 patients with displaced acetabular fractures were reviewed to compare the long-term results of operative versus nonoperative treatment. Of 90 patients followed up to 8 years (mean, 4 years, 9 months), 54 were treated operatively and 36 nonoperatively. Experience in pelvic trauma surgery was of significance both in choice of treatment and success in achieving optimum results. Assessment by a new acetabular fracture score showed that anatomic or near-anatomic restoration of the joint led to 86% excellent or good results compared with 30% good results for fractures remaining moderately or severely displaced.