Purpose: This study aimed to determine the prevalence of common anatomical variations of paranasal sinuses by computed tomography (CT) images among the study population of patients attending OPD of ENT Department with complaints of chronic cold, nasal blocks, headache, etc. Methodology: This observational study comprised of 124 patients who were recommended for FESS and were referred to the Radiology Department for CT scan of PNS between July 2019 to December 2019 at MIMS, Mandya. Various anatomical variations were evaluated, associated with the genders & age groups. Results: The results showed both right and left sinuses were involved maximum in the maxillary sinus in 45(36.3%), ethmoidal sinus in 27 (21.8%), sphenoid sinus in 7(5.6%), paradoxical middle turbinate in 15 (12.1%), aggar Nasi cells- 80 (64.5%) and maxillary sinus septations in 8 (6.5%). Choncha Bullosa was found in eighteen cases (14.5%) on right side, twelve (9.7%) on left side and bilateral in eighteen (14.5%) cases. Left side sinus was involved more in Frontal sinus-8 (6.5%). Right side sinus was involved more in maxillary sinus 24(19.4). Right side involvement was found in Haller cells-7 (5.6%), Onodi cells-11 (8.9%), and anterior clinoid process (ACP) Pneumatization in 13(10.5%) of the subjects. Conclusion: It is extremely essential to know common anatomical variations of paranasal sinuses pre-operatively as they serve as a roadmap for ENT surgeons cautioning them in advance about the risks of damaging the normal structures thinking as pathology.