Previous studies have shown that cystic fibrosis (CF) gene mutations are linked to several severe chronic infections. Chronic sinusitis is one condition that may well be influenced by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. We studied two prevalent CF mutations (AF508 and 394delTT) in a population with a low incidence of CF. The carrier frequency of the CF mutations in the Finnish population is approximately 1 in 80. We examined DNA specimens from 127 chronic sinusitis patients and found one patient who was heterozygous for 394delTT gene mutation. None of the DNA specimens had any AF508 mutation. This study shows that in a population with a low incidence of CF there was no abnormal carrier distribution of the two most common CF gene mutations in a group of chronic sinusitis patients. Routine screening of sinusitis patients for CF mutations provides no additional information on the etiology of chronic sinusitis.