AbstractA group of 85 patients with roentgenological evidence of asbestosis were examined on two occasions within a three‐ to four‐year interval, first in 1976‐1977 and again in 1979‐1981. During this follow‐up period, the asbestosis (interstitial pulmonary fibrosis) of 26 (31%) showed progression. The cases with either moderate or advanced fibrosis showed progression more often than those who initially had manifested only slight fibrosis. Included in the group whose interstitial fibrosis showed radiographic progression were asbestos sprayers and cigarett