Although the prevalence of the deviated nasal septum (DNS) is high, the number of asymptomatic person with DNS is higher than that of symptomatic patients. Most of the patients complain nasal discomfort in narrow side. Usually clinical laboratory tests are performed at each side separately; therefore it is very difficult to evaluate the both nasal cavities simultaneously. The purpose of this study is to evaluate the difference in aerodynamic parameters with presence of nasal symptoms, using PIV and CFD methods in asymmetric nasal cavities due to DSN. Aerodynamic parameters, such as velocity, flow rate in both nasal cavities, wall pressure and wall shear stress were evaluated in 2 symptomatic and 2 asymptomatic patients with DSN. Surface-rendered bilateral nasal cavity models were created from CT scans and used for making clear models for investigation with PIV method and for numeric method. Flow rates in both nasal cavities were different in symptomatic patients with PIV method and CFD method. High wall shear stress was noted at the narrow side of the symptomatic patients. These parameters can be used for the evaluation of the patients with nasal discomfort with CFD method.