In this study, we performed a bidirectional two-sample MR analysis based on summary-level data of genome-wide association studies (GWAS) to explore the effect of nine commonly mentioned peripheral inflammatory factors [TNF-α, CRP, IL-1α, IL-1β, IL-2, IL-6, soluble IL-6 receptor alpha (sIL-6Rα), soluble gp130, and IL-8] on the risk of delirium. This evidence concerns the gene IL1A and delirium.