Background and Objectives：The purpose of this study was to evaluate the correlation of nasal septal deviation and coexistent inferior turbinate hypertrophy of both side. It also focused on proportional relationships between nasal septal deviation and each compartment of inferior turbinate hypertrophy. Materials and Method：PNS CT of 106 patients treated during the period from September, 2001 to July, 2002 at the Keimyung University Dongsan Medical Center were reveiwed retrospectively to measure nasal septal deviation angle and inferior turbinate hypertrophy. Using PACS (picture archiving and communicating system), we measured the thickness of medial and lateral mucosal, conchal bone by 0.1 mm unit. Each measurement was compared according to the degree of septal deviation angle and its correlation to the co-existent turbinate hypertrophy was analyzed. Results：Inferior turbinates of the concave side were more hypertrophied when compared with the convex side (p<0.05) and its medial mucosa and conchal bone thickness were also increased more in the concave side (p<0.05). However, in view of correlations, there was no statistically significant relationship between septal deviation angle and the degree of hypertrophy of medial, lateral mucosa and conchal bone of inferior turbinate. Conclusion：Although it is a common belief that the nasal septal deviation may cause inferior turbinate hypertrophy of the concave side, there is a possibility of another explanation for this phenomenon, such as the developmental theory.