Postsurgical stability of mandibular setback to correct class III malocclusion was studied in 14 patients whounderwent sagittal split osteotomy with circummandibular wiring and elastic IMF. Lateral cephalograms were analyzed before surgery, immediately after surgery, and at least 6 months after surgery, using three linear measurements. A simple regression analysis was used to determine the relationship between skeletal relapse and the magnitude of mandibular setback. Methods for preventing relapse are discussed.