Objective: Patients with a diagnosed OSA often differ in the cephalometric characteristics from the healthy control subjects. The aim of this study was to investigate the difference of soft tissue, dental and skeletal cephalometric characteristics in patients with mild or moderate OSA compared to patients with severe OSA. Materials and methods: This retrospective study included 32 subjects with diagnosed OSA who had previously undergone polysomnography at the Sleep Medical Center at University of Split School of Medicine and University Hospital of Split. At the Dental Radiology Center X-Dent, latero-lateral head radiograph was recorded. Cephalometric analysis of the recordings was carried out in the computer program AudaxCeph (Audax, Ljubljana, Slovenia). After reviewing the polysomnographic findings, subjects were divided into two groups: patients with mild or moderate OSA (5 < AHI < 30) and patients with severe OSA (AHI ≥ 30). Cephalometric analysis evaluated nine soft tissue, eight dental and eighteen skeletal variables in each group of subjects, which could be affected by the development of OSA. Results: Measurement of soft tissue structures on the latero-lateral head radiograph revealed significantly greater length of soft palate (SPL) in patients with severe OSA compared to those with mild or moderate OSA (48.9 ± 5.2 mm vs. 43.3 ± 4.6 mm, P = 0.004). Other soft tissue structures did not show statistically significant difference between the two groups of patients. The results of measurements of cephalometric dental and skeletal parameters also did not show a statistically significant difference between patients with severe OSA and patients with mild or moderate OSA. Conclusion: Based on the results of this study we can conclude that there are differences in cephalometric characteristics among patients with different severity of OSA. There were significant differences in the measurements of the soft-tissue structures, specifically in soft palate lenght. There were no other significant differences in cephalometric measurements between the patients with mild or moderate OSA and those with severe OSA.