Introduction: Skeletal alterations are variations that occur in the jaws and occlusion. In addition, these can generate problems in the pharyngeal airways. For this reason, different procedures arise to correct bony problems, such as orthognathic surgery. However, these surgical techniques do not fully prove significant changes in the upper and lower pharyngeal airways. Objectives: To determine the anteroposterior dimensional changes of the upper and lower pharyngeal airways in lateral skull radiographs of patients undergoing orthognathic surgery. Methodology: A descriptive observational study was carried out. Cross-sectional. The sample included 24 lateral cephalic radiographs of patients between 18 and 60 years of age who underwent orthognathic surgery. Proportions were calculated for qualitative variables and measures of central tendency and dispersion for quantitative variables. For cephalometric variables before versus after; the paired Student's t-test or the Wilcoxon sign test was applied according to the distribution of the data, additionally the Pearson correlation coefficient was applied to relate the dimensional changes of the pharyngeal airways with the SNA and SNB planes. A significance level of α ≤ 0.05 was considered for the analysis. Results: It is important to highlight that for maxillary retrocession surgery there were statistically significant differences before and after the surgical process (p=0.0023) since thanks to this surgery the patients had 1.7 mm more in their upper pharyngeal space. While the forward and also the mandibular backward surgeries allowed them to gain 1.5 (p=0.0108) and 1.8 mm (p=0.0184) in this same pharyngeal space. Conclusion: Twenty-four lateral skull radiographs were evaluated, in which it was possible to determine changes in the amplitude of the upper and lower pharyngeal airways, which could have been produced by the set of surgical procedures to which each of the patients underwent.