One hundred-fourteen computed tomographic (CT) scans of the skull region were revised for occult sinus pathology in asymptomatic individuals. The scans were conducted to investigate other skull regions. None of the patients had nasal or sinus symptoms. Twenty-nine percent of the ethmoid sinuses had occult pathology mostly in the form of thickened mucous membrane. Occult pathology occurred in 14% of maxillary sinuses, 4.8% of the frontal sinuses, and 4.6% of the sphenoid sinuses. As ethmoids carry a high incidence for possible occult pathology, isolated clouding of the ethmoids in CT scans should not be regarded as a cause for patients' symptoms especially in headache investigation. MMS Taher, OS Haddad, CT Scan Findings of Occult Sinus Pathology in Asymptomatic Individuals. 1992; 12(5): 456-458Inflammatory and allergic changes of the paranasal sinuses can usually be demonstrated radiologically. These are usually in the form of mucosal thickening, air fluid level, or total sinus opacification. In chronic cases of sinusitis it is possible to have thickened sclerotic sinus walls [1].However, conventional radiography showed that between 15% and 26% of asymptomatic individuals have abnormal x-ray findings of probable inflammatory or allergic origin [2,3].Also, mucocele of the maxillary sinus is not a rare incidental radiological finding. It is present in almost 10% of cases [4].Again, in some cases, plain radiography failed to grasp gross pathology in the paranasal sinuses. Watt-Boolsen and Karle (1977) [5], and Pfleiderer et al (1984) [6], discovered fluid in the antral puncture in 24% and 9%, respectively of radiologically normal sinuses, but clinically suspected to have sinusitis.Computed tomography (CT) is now the best measure for imaging the sinuses [7], and clinically significant ethmoid disease may be present with relatively minimal plain radiological findings that would be quite evident on CT scan [8][9][10].In this work, CT scans of paranasal sinuses were studied for possible occult pathology in asymptomatic individuals. Material and MethodsOne hundred fourteen CT scans of the skull region were studied. None of the scans was conducted to investigate the paranasal sinuses specifically, but were to study the orbit, sella turcia, facial bones, or parotid region.Some of the paranasal sinuses came to appear incidentally in some of the cuts. The age range of patients was between 18 and 61 years, with a mean age of 36 years. Fifty-four percent of the patients were males.The CT scans were reviewed by the author retrospectively to locate any benign occult pathology, namely sinus