Background: Diabetes appears to be associated with the development of pancreatic cancer. Three large prospective cohort studies observed a statistically significant relation between obesity and pancreatic cancer risk. Dietary patterns have been associated with fasting insulin levels and risk of diabetes. To determine whether dietary patterns are associated with pancreatic cancer risk, we analyzed data from two large prospective cohort studies. Methods: We combined data for men and women to obtain a total of 366 cases of incident pancreatic cancer from a total of 124 672 eligible participants. Dietary data were obtained from food frequency questionnaires in 1986 for men and in 1984 for women. We identified two major dietary patterns, prudent and western, by factor analysis. The prudent pattern was characterized by high fruit and vegetable intake; the western pattern was characterized by high meat and high fat intakes. Multivariable relative risks (RRs) were adjusted for potential confounders, including smoking and body mass index. Results: In the pooled analysis of men and women, no associations were observed between the prudent pattern (RR = 1.32, 95% confidence interval [CI] = 0.66 to 2.63, for highest versus lowest quintile) or the western pattern (RR = 0.91, 95% CI = 0.57 to 1.47, for highest versus lowest quintile) and the risk of pancreatic cancer. Stratifying by body mass index or physical activity did not change the associations. Conclusion: Dietary patterns were not associated with the risk of pancreatic cancer in two large cohort studies of men and women.