Age-adjusted mortality rates for non-Hodgkin's lymphoma in counties of the contiguous United States were examined by sex and race during 1950 to 1975 and were correlated through 1969 with demographic and industrial data. Mortality was consistently elevated in counties with large populations, especially in those with higher income and education levels. Among males, but not females, elevated rates appeared in counties with high percentages of residents of Russian or Greek descent. A series of contiguous counties with high rates was seen along the coast of California. Lower rates in the South were explained in a multivariate analysis by the generally lower socioeconomic levels in this region. Counties with industrial concentration in food packing showed higher mortality rates among males than did comparable counties without these industries. All regions and all sex-race groups showed an increase over time in mortality from non-Hodgkin's lymphoma, especially reticulum cell sarcoma.