The advent of functional endoscopic sinus surgery (FESS) has revolutionized the treatment of chronic sinusitis over the last decade. Although it has been well-established that FESS is more efficacious than conventional surgery, the lack of a quantifiable means of assessing results remains one of the major shortcomings of the technique, and hence a source of criticism. Since the pathophysiology of chronic sinusitis is intimately related to the mucociliary mechanism of the nose and sinuses, it seems logical to use this parameter as a yardstick of success. We undertook a prospective, controlled study of 40 patients and measured their “saccharin times” before and after surgery. The results show a marked reduction in clearance times postoperatively, corresponding well with improvement in symptom profile. We therefore propose this technique as a simple, safe and reliable method of assessing the results of surgery. Furthermore, the method could act as a preoperative indicator of ciliary motility disorders, as the prognosis in these patients is distinctly poor.