Introduction Concha bullosa (CB) is the most common sinonasal anatomical variation reported in literature, it occurs most often in the middle turbinate. Causes of development are not clearly identified but coincident prevalence with deviated nasal septum (DS) is common.

Objective To study the relationship between DS and development of CB. Methods A prospective study including 40 patients with DS, CT scans were thoroughly analyzed to detect the presence of CB, its type, and laterality. Effect of degree of septal deviation from the midline and level of deviation in the axial plane were also addressed.

Results The study included 40 patients with DS; 15 of them had associated CB; the lamellar type of CB was the most prevalent followed by the true type. 

Conclusion Incidence of CB was higher in patients with increased angle of septal deviation and with lower level of deviation in the axial plane.