Background: Deviated nasal septum (DNS) is an influential variant of the sinonasal region due to its possible association with varied sinonasal pathologies, mid-facial (skeletal or occlusal) disharmonies and orofacial pain disorders. The aim of the study is to document the prevalence of DNS and to observe and assess the radiographic attributes of its types in adults. Materials and Methods: It is a descriptive cross-sectional study in which, after getting ethical approval, computed tomography paranasal sinus volumes of 100 adult subjects are collected from the medical college on the basis of convenience sampling. Paediatric subjects and patients with a previous history of mid-facial trauma, malignancy or surgery are excluded from the study. DICOM data thus collected are retrospectively analysed by RadiAnt DICOM viewer to determine the prevalence of DNS to study its association across gender and with increased (>1 mm) mucosal thickening of the maxillary sinus. DNS is recorded by Mladina’s classification and by septal deviation angle, and association is studied by the Chi-square test and Mann–Whitney U test. Results: The overall prevalence of DNS is 82%. Association of deviated septum with gender and mucosal thickening of the sinus lining is not statistically significant. Overall type V (spur) deviation is most common; however, in subjects with thickened mucosal lining type III (“C” or reverse “C”), deviation is found to be most prevalent. All the cases of type VI deviation have a tilted nasal floor, a finding of dental surgeon’s interest. “Bridging Spur,” an uncommon form of spur deformity, is also recorded in one case. Conclusions: Deviated septum is far more common than straight septum in the adult population. Types III, II and IV are more frequent in subjects with increased mucosal thickening. Association of type VI with tilted floor and rare variants like “Bridging spur” is also reported.