Mucocillary clearance of nasal mucosa was evaluated with the saccharin test. A total of 140 subjects was divided into 4 groups: smokers, allergic rhinitis patients, sinusitis patients, and a normal control group. The mean mucociliary transit time for the normal control group (n = 40) was 12 minutes, while allergic rhinitis patients (n = 40) had a mean of 14.6 minutes. The smoker group (n = 40) could be further divided into the following subcategories: (a) those who had been smoking for less than 5 years (n = 10) had a mean of 15.2 minutes, (b) those who had been smoking for more than 5 years at less than one-pack a day (n = 11) had a mean of 14 minutes, and (c) those who had been smoking for more than 5 years at more than one-pack a day (n = 19) had a mean of 16.5 minutes. For the sinusitis patients (n = 20) the mean was 16.6 minutes. The study shows that sinusitis patients, along with those smokers who had been smoking for more than 5 years at more than one-pack a day, had a mucocillary transit time that was considered to be prolonged when compared to the normal control group (p < 0.05).