© 2022 Lippincott Williams and Wilkins. All rights reserved.Purpose: To evaluate the effects of upper occlusal plane (UOP) inclination and incisor decompensations on the outcome of surgical Class II patients. Materials and Methods: Pretreatment (T0), preoperative (T1), and posttreatment (T2) cephalograms of 30 surgical Class II patients were included. Cephalometric measurements were performed using the Dolphin Imaging Software in this retrospective study. The differences between time points were analyzed with repeated measures ANOVA. Spearman correlation test was used to determine any correlations between either the UOP alterations or incisor decompensations and the cephalometric variables. Results: A significant improvement was obtained in the sagittal skeletal, dental variables, and soft tissue B point. Significant correlations were found between the decompensation achievement ratio and the change of the convexity angle. The relative percentage ratio (RPR) of the lower incisor was correlated with Wits appraisal, ANB, and Convexity Angle at the T2 stage. The RPR of the upper incisor was found to be correlated with lip strain. The relative surgical correction ratio of the UOP angle was found to be correlated with the surgical change of Wits appraisal and convexity angle. The RPR of the UOP angle was correlated with the SNB, ANB, and SN-GOGN angles at the T2 stage. Conclusions: Significant improvement in the incisor inclinations was achieved, but the incisors were inadequately decompensated at the preoperative phase. Surgical correction was limited by the inadequate presurgical decompensation. The surgical alteration of the UOP should be taken into consideration for the surgical planning to obtain better outcomes for Class II patients.