Background: Pharynx is located in close proximity of dentofacial structures. Therefore, a relationship might exist between skeletal malocclusions and the size of the pharyngeal airway.Objectives: The aim of the present study was to assess and compare the upper airway dimensions and characteristics of skeletal Class I and Class II patients using cephalometric analysis.Patients and Methods: In this retrospective study, lateral cephalograms of 24 Class I and 26 Class II patients, Who were 9-11 years old and had the inclusion criteria, were used for analysis. Cephalograms were traced manually. Depth of the nasopharynx, oropharynx, and hypopharynx, soft palate dimension and position, and hyoid position were measured on the cephalograms. Independent-samples t-test was used for analyzing the differences in the variables of the two groups and Pearson correlation analysis was used for finding any association between the variables.Results: No significant difference in the upper airway, soft palate, and hyoid variables was found between the two groups (P>0.05) and no correlation was found between ANB difference and the other variables (P>0.05).Conclusions: Pharyngeal airway dimensions, soft palate length, thickness, and position, and hyoid position are not significantly different between skeletal Class I and Class II prepubertal children.