In nasal septal deviation, the deviated narrow side is more frequently combined with sinusitis due to the mechanical obstruction of ostiomeatal unit. The purpose of this study was to determine whether reduced airflow has a harmful effect on nasal inflammation and the development of rhinosinusitis. Twenty-three healthy New Zealand white rabbit were used. One side of the nostril was closed in 15 rabbits and 5 rabbits served as control. Rabbits were sacrificed at 4, 8 and 12 weeks. The anterior maxillary and septal mucosa were obtained for EM and LM study. Mucociliary clearance rate was measured using the India ink method. At 4 weeks, the opened side mucosa showed ciliary losses and ulcerations in the mucosa, but at 8 and 12 weeks, the closed side showed more severe ulceration and ciliary loss than open side. The mucociliary clearance rate was 12.3 mm/min in the control group, but the open side was 8.7 and 7.1 mm/min and the closed side was 4.7 and 6.4 mm/min at 4 and 8 weeks, respectively. Electron microscopy showed many abnormal cilia at 8 weeks in both sides. These observations suggest that inadequate airflow is an important causative factor of nasal and sinus infection, and that patients with septal deviation have a similar chance of developing sinusitis in either side.