Variations of the nasal cavity are very important for the otolaryngologist in functional endoscopic sinus surgery. To provide data on bony variations of this region, we performed high resolution computed tomography images of paranasal sinuses on 82 adult patients without sinus pathology and on 90 adult patients with sinus disease. We observed paradoxical curvature of the middle concha in 11 (12.22%) sinus patients and 6 (7.31%) in non-sinus patients. Concha bullosa was observed in 26 sinus patients (28.88%) and 22 (26.83%) in non-sinus patients, deviated nasal septum in 20 (22.22%) sinus and 10 (12%) non-sinus, Haller's cell in 5 (5.55%) sinus and in 3 (3.65%) non-sinus, agger nasi cell in 7 (7.77%) sinus and 4 (4.88%) non-sinus patients. Pneumatisation of cristae galli was observed in 8 (8.88%) sinus and 2 (2.44%) non-sinus, of the anterior clinoid process in 5 (5.55%) sinus and 1 (1.22%) non-sinus patients, pneumatisation of the nasal septum in 7 (7.77%) and of the pterygoid recess in 12 (13.33%) sinus patients. We did not find any correlation between age intervals and paranasal sinus variations, and also no statistically significant difference was observed between males and females. These data provide very important information to guide the otolaryngologist and/or radiologist in the evaluation of patients with coronal CT which guides functional endoscopic sinus surgery.