Concha bullosa is one of the most common, obstructive and anatomic variants seen in patients with chronic rhinosinusitis. Following introduction of an endoscopic tool in diagnosis and treatment of sinus surgery, computed tomography has gained a major role in preoperative radiologic evaluation of paraneasal sinuses. So, it is a interesting viewpoint that how much proportion of concha bullosa is occupied in chronic rhinosinusitits and concha bullosa may a play role in the development of chronic rhinosinusitis. In this study, a total 173 computed tomographies were reveiwed, which of patients received endoscopic sinus surgery in our department. The results were as follows : 1) The presence of concha bullosa does not have an effect on the mucosal changes of paranasal sinuses significantly except posterior ethmoid and sphenoid sinus. 2) There was no significant difference in existence of concha bullosa between the chronic rhinosinusitis and non-chronic rhinosinusitis group and the result was same, according to the types of concha bullosa. 3) The other variants which was anatomically closely related with concha bullosa, were significantly increased in concha bullosa group. In conclusion, concha bullosa may not be considered as unique etiologic factor in development of chronic rhinosinusitis. However, concha bullosa was associated with limited mucosal change and accompanied more frequently anatomic variants.