Effect of deviated nasal septum and after its correction on nasal mucociliary clearance (NMC) values which was measured preoperatively and postoperatively using Anderson's method, was observed. Mucociliary clearance time in 20 patients suffering from deviated nasal septum was studied preoperatively and 2 months postoperatively. In the preoperative period, NMC values were significantly higher than the values measured after septoplasty. The NMC values of the control group and the NMC values of patients after septoplasty were not found different significantly. This study shows that deviated nasal septum affects NMC values which improve after septoplasty.