The mortality experience of 415,309 men enrolled in the Canadian Labour Force 10% Sample Study has been updated to the end of 1979. The occupation and industry in which these men were employed between 1965 and 1969 were available, and these records were matched to the Canadian National Mortality Data Base by computerized record linkage. A total of 9,739 deaths from cancer between 1965 and 1979 were identified. Analyses were conducted with respect to men employed in 274 occupations and 294 industries with respect to mortality from 33 different types of cancer resulting in 243 associations in which the 90% lower confidence bound for the relative risk compared to the whole cohort had a value of 1.0 or greater. Based on the criteria of strength of association, dose-response, and consistency, 23 associations were identified as being of particular interest. Of these associations, four (waiters, bartenders and breweries with cancer of the buccal cavity and pharynx, and bartenders with lung cancer) seem most likely to be caused by excess smoking and/or alcohol consumption, and could provide a useful guide for intervention strategies focused on those employed in these occupations. A further seven (carpenters and stomach cancer, clerical occupations and colon cancer, truck drivers, plumbers and pipefitters, sheet metal workers, shipbuilding and repair, and asbestos products manufacturers with lung cancer) have support in terms of biological plausibility and/or other studies in the literature and appear to warrant more intensive study. The third group of associations, although demonstrating strength of association, a dose-response effect, and/or consistency, may well have arisen by chance given the many comparisons made in this study.