The prevalence of rheumatic diseases was studied at a mass screening in a brick-yard in Pervouralsk. Altogether 2190 persons were examined, of them various rheumatic diseases were detected in 1049 (47.89%): inflammatory in 6.66%, degenerative in 93.34%. A study was made of the structure of rheumatic diseases. Diseases of the locomotor system of degenerative nature were shown to rank first in the structure of rheumatic incidence. A decrease in rheumatic fever prevalence (0.68%) as compared to national rates (1.5 +/- 2.0%) was noted. Two cases of silicoarthrosis, 5 cases of sclerodermia systematica and 2 cases of Caplan's syndrome were detected.