As part of a large cross sectional epidemiological study of respiratory disease in coalminers, the respiratory health of miners in one colliery in south Wales has been compared with the health of nearby telecommunication (telecom) workers. The studies were carried out in 1981 and 1982. The answers to questionnaires on respiratory symptoms and results of lung spirometry indicate a much greater frequency of respiratory ill health among the miners than the telecom workers. The frequency of symptoms of chronic bronchitis among the current employees was 31% in the miners and 5% in the telecom workers, and these symptoms were reported as frequently by younger as by older miners. Reports of other respiratory symptoms showed similarly large differences between current miners and telecom workers. These differences were seen both within non-smoking and smoking groups. Comparisons of FEV1 with predicted values (several different predictions were used) confirmed that the differences in reported symptoms were accompanied by differences in lung function; of the order of 20% of current miners had an FEV1 less than 80% of predicted compared with 10% of current telecom workers. The excess of respiratory disease shown among these miners is not necessarily a consequence of the dust concentrations currently experienced underground, nor is the colliery necessarily representative of the coal industry generally. The findings, however, indicate the continued need for measures to improve the respiratory health of these men.