The characteristics of the 3614 Los Angeles County residents in whom cancer of the exocrine pancreas was diagnosed during the period 1972-1977 were compared with those of all county residents and patients in whom any cancer was diagnosed during the same period. Seventy-nine percent of the diagnoses had been pathologically verified. This disease still preferentially afflicts the old, the black, and men, although the differences in risk with factors other than age are modest. The disease is not evenly distributed by social class, or over time, although it is not clear that the observed differences reflect etiology. The distributions with respect to important categories of occupation and industry, religion, marital status, geography of residence, and birthplace were rather uniform. Although there is no obvious explanation for any of several unexpected minor inequities in the pattern of incidence, there is no compelling evidence to support any specific environmental cause. There is substantial evidence which is inconsistent with those environmental hypotheses that have been proposed previously.