Aim: To evulate relationship between nasal septal deviation and concha bullosa (CB) by using deviation angles and concha bullosa pneumatization index (CBPI). Method: Ninety patients with both nasal septal deviation and CB were evaluated by computerized tomography (CT) of paranasal sinus in coronal plane. Deviation angles and concha bullosa pneumatization index (CBPI) was calculated. Paranasal sinus pathologies were recorded on paranasal sinus CT. Result: Contralateral, ipsilateral and bilateral CB according to nasal septal deviation were found in 45 (50%), 16 (17.8%) and 29 (32.2%), respectively. Contralateral CB was significant higher than ipsilateral CB (p<0.05). CBPI and deviation angle in the patients with contralateral CB were significant higher than in the patients with ipsilateral CB (p<0.05). In contrast, there was not any association between ipsilateral sinus pathology and nasal septal deviation and CB (p>0.05). Conclusion: Results suggested that there was a significantly relationship between nasal septal deviation and contralateral CB.