Data from the 1978-1980 National Health Interview Survey smoking questionnaire were used to analyze prevalence and levels of cigarette smoking among groups of US workers. This information is valuable for indirect adjustment in occupational epidemiology studies as well as for describing smoking patterns of workers in a wide range of job settings. Although there was a higher percentage of current smokers among men than women in the general population, there were few differences in prevalence of smoking among men and women for specific occupations. Also, race and employment status had an influence on prevalence of smoking, where both the currently unemployed and blacks generally had a higher proportion of current smokers, although blacks generally had a higher proportion of current smokers, although blacks smoked fewer cigarettes. Industry also played a major role in the variation of smoking habits. For instance, the percentage of current smokers of a given occupation had as much as a 25% difference depending on the industry they were employed, such as 52% vs 26% for managers and administrators. Detailed data will be made available as microcomputer files for interested researchers.