Because of a reported association between residence in counties with nonferrous smelters and increased risk of lung cancer, we studied the relationship between distance of residence from nonferrous smelters and lung cancer. Patients with lung cancer and patients with other cancers not known to be associated with smelter effluent (breast, prostate, and colon) were compared. All patients lived within a 20-kilometer radius around one of 10 nonferrous smelters in five western states during 1970-1977. Data were obtained from cancer registries or death certificates and were examined separately for each area. Addresses at the time of diagnosis or death were plotted on U.S. Geological Survey maps to calculate distance from each smelter. The distribution of lung cancer near the smelters was not significantly different from the distribution of control cancers in any of the areas studied.