Background Whether adherence to the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) cancer prevention recommendations is associated with a reduced risk of pancreatic cancer remains controversial. Additionally, no study has investigated this association in the US population. Hence, we investigated the association of adherence to the 2018 WCRF/AICR cancer prevention recommendations with pancreatic cancer incidence and mortality in a US population. Methods A population‐based cohort of 95 962 participants was identified. A score incorporating eight WCRF/AICR components was constructed to reflect adherence to the WCRF/AICR guidelines, with higher scores representing greater adherence to the guidelines. Cox and competing risk regression were used to calculate risk estimates for pancreatic cancer incidence and mortality, respectively. Restricted cubic spline functions were used to test nonlinearity. Results In the fully adjusted model, higher overall WCRF/AICR scores were shown to be associated with lower risks of developing pancreatic cancer (hazard ratiotertile 3 vs 1:0.67; 95% confidence interval: 0.49, 0.90; Ptrend = .0099) and mortality due to this cancer (subdistribution hazard ratiotertile 3 vs 1 0.65; 95% confidence interval: 0.47, 0.89; Ptrend = .0108) in a linear dose–response manner (all Pnonlinearity > .05). The component “be physically active” was shown to be a key contributor to the observed associations. No association of the diet‐specific WCRF/AICR score with pancreatic incidence and mortality was found. Conclusions Adherence to the 2018 WCRF/AICR guidelines, especially “be physically active,” confers reduced risks of pancreatic cancer incidence and mortality in the US population; however, adherence to dietary components alone does not confer such beneficial effects. In this prospective study of 95962 American adults, we found that greater adherence to the 2018 WCRF/AICR recommendations was associated with lower risks of pancreatic cancer incidence and mortality. However, such beneficial effects were not found for adherence to diet‐specific recommendations alone.Importantly, the component “be physically active” was found to be a key driver of the observed associations.