About 100 patients with cystic fibrosis (CF) from the European part of Russia were screened for mutations 2143delT, 2184insA, S1196X, 3732delA, and W1282X. The patients had one or two mutations (other than delta F508) in CF chromosomes. The frequency of these mutations were estimated in CF chromosomes without the delta F508 mutation. The frequencies of mutations 2143delT, 2184insA, S1196X, and W1282X were 2.9, 7.4, 2.2, and 4.8%, respectively. Linkage was found between allele 6 of the variable site (a tetranucleotide repeat in intron 6 of the gene for CF) and mutations G542X and 2143delT, as well as between allele 7 and mutations R334W, 2184insA, S1196X, and W1282X. Except for delta F508, the most common mutations were 2184insA, 2143delT, and W1282X.