Functional endoscopic sinus surgery (FESS) is the surgical treatment of choice for many physicians in chronic inflammatory diseases of the sinuses. Although subjective benefit has been claimed after surgery, there are not enough studies reporting objective improvement. We evaluated 40 patients undergoing FESS for chronic and recurrent sinusitis with visual analog scale (VAS) scoring of sensation of nasal obstruction and active anterior rhinomanometry of nasal resistance. The results of postoperative measurements demonstrated that baseline total nasal resistance measured with rhinomanometry and evaluated with VAS scoring (baseline and after decongestion) were significantly lower than preoperative measurements. However improvement in nasal resistance was not statistically significant after decongestion, whereas VAS scoring was. These findings indicate that FESS improves nasal mucosal edema but does not change the structural anatomy of the nose.