The epidemiology of occupational lung cancer was considered with emphasis on agents identified as definite or probable pulmonary carcinogens by the International Agency for Research on Cancer. Topics that were addressed included: detailed discussions of specific agents (silica (14808607)), asbestos (1332214), diesel engine exhaust, radon progeny, arsenic (7440382), acrylonitrile (107131), chromium (7440473), beryllium (7440417), nickel (7440020), and cadmium (7440439)) to which large numbers of workers may be exposed; and attributable risk. The methodology for determining attributable risk was based on estimating the proportion of the population exposed to specific occupational carcinogens and using estimated relative risks for these carcinogens. Estimates of overall relative risks were derived using previously reported data from major studies. Inverse variance and a random effects model were used for these calculations. The authors estimate that approximately 9,000 to 10,000 men and 900 to 1,900 women develop lung cancer annually in the United States due to past exposure to occupational carcinogens. More than half of these cases can be attributed to asbestos exposure. The number of attributable cases is likely to decrease in the future unless new carcinogens are introduced or others are discovered.