The paranasal sinuses are hollowed, air-filled cavities surrounding the nasal cavity. Many pathological processes affect the sinuses, but inflammatory conditions are the commonest, even in asymptomatic patients who undergo head imaging for other indications showing one or more abnormalities of the sinuses. Our research aims to determine the prevalence of incidental paranasal sinuses abnormalities seen among patients who undergo head CT scanning. In addition, it provides baseline information for further investigations required. The study was designed to evaluate all patients who underwent head CT scanning for any reason unrelated to paranasal sinuses abnormalities. 1849 cases were selected and retrospectively analyzed from the elective and emergency CT in the last nine months, from August 2020 to April 2021. In order to meet the inclusion criteria, indications for imaging must not be sinus-related. The study was conducted on 1849 cases who had undergone head CT scans for pathology, 1204 (65%) were male and 645 (35%) were female. Abnormalities of the sinuses were found in about 617 (33%) of all patients, with a higher rate in males (22.23%) than females (11.14%). In addition, these abnormalities were found in younger patients at a higher rate than in middle and old ages 19.74%, 7.19%, and 6.44%, respectively. Our findings revealed that the prevalence of paranasal sinuses abnormalities in asymptomatic Saudi patients was high (33%). Most of the affected sinuses were the maxillary. The male patients were more affected than females in all findings.