Abstract: Background and Objective: Now-a-days computed tomography (CT) has become the investigation of choice for the diagnosis of the paranasal sinuses (PNS) pathologies. This study was designed with an aim to determine the role of computed tomography in classification the spectrum of PNS pathologies in Saudi patients. Materials and Methods: A total of 100 PNS CT patients were prospectively examined during the period extending from October 2018 to October 2019. A 128 detector CT scanner (Workstation Intellispace ISP; Philips, Netherlands), was applied to investigate patients with suspected PNS abnormalities at Radiology and Medical Imaging Department at King Khalid Hospital and Prince Sultan Center for Health Services in Al-Kharj, Saudi Arabia. Results: Out of the 100 patients – 56% males and 44% females with male to female ratio of 1.3:1 – Maxillary sinuses were the most sinuses that affected by sinusitis (68%) and the frontal sinuses was the last one (30%). The most common pathology seen was sinusitis in 79% cases. Atrophy, polyp and hypoplastic disease were detected in (1%) of cases. Most common anatomical variations were closed osteomeatal complex (86%), inferior nasal turbinates muscle hypertrophy (54%) and deviated nasal septum (83%). Conclusion: The CT was able to characterize the PNS diseases along with their extension. The most common pathology was sinusitis with 68, 55, 35 and 30% in the maxillary, ethmoid, sphenoid and frontal sinuses, respectively. Most common anatomical variant seen was nasal septum defect while the most commonly sinus involved was maxillary. It proves the better sensitivity (98.04%), specificity (80%) and accuracy (97.02%) of CT in the evaluation of various sinonasal pathologies.