The vertical facial proportions resulting from bimaxillary surgery (maxillary advancement and mandibular setback) and mandibular setback alone were evaluated. The measurements were evaluated on the preoperative and postoperative cephalometric radiographs of 20 skeletal Class III patients. The results showed that sagittal correction of the jaws caused no change in the vertical relationship of the jaws. The only significant change was an increase in occlusal plane inclination in bimaxillary surgical patients. (Int J Adult Orthod Orthognath Surg 2001;16:30–35)