The Paranasal sinuses are complex anatomical structures. They have many functions, such as lighting the skull of the human and imparting resonance to the voice and secretion of mucus to moisten the nasal cavity. Imaging paranasal sinuses by Multidetector computed tomography is the gold standard to assess any lesions in them. The aim of this work was to assess the role of multidetector computed tomography in diagnosis of paranasal sinuses lesions. A prospective study included 40 patients of both males and females with an age ranged from 22 days to 57 years referred from Ear, Nose and Throat department in Al-Zahraa university hospital in the period between January 2020 to June 2021. CT Para nasal sinuses were performed without contrast medium in some patients and with contrast media in suspected cases of complicated sinusitis or neoplasia. The mean age ± SD of the patients were 27.7 ± 12.8, males were more affected than females, smoking is contributing factor in paranasal sinuses lesions, the predominant chief presenting complaint was thick nasal discharge, common CT finding was thickened mucosal lining, most common diagnosis was chronic sinusitis, and most affected sinus was maxillary sinus. CT is an excellent imaging modality for evaluating the pathologies of PNSs.