This study aimed to thoroughly examining the causal link between immune traits and four types of pancreatitis, using mendelian randomization.Data on 731 immune traits were collected from the genome-wide association study (GWAS) database as exposure. Information regarding acute pancreatitis (AP), alcohol-induced acute pancreatitis (AAP), chronic pancreatitis (CP), and alcohol-induced chronic pancreatitis (ACP) were acquired from the FinnGen Consortium as outcomes. Mendelian randomization (MR) using inverse variance weighting (IVW) evaluated the links between immune traits and pancreatitis. We evaluated the robustness of the IVW results through sensitivity analyses and validated them using meta-analysis with AP and CP data from the UK Biobank in the GWAS catalog.A total of 36 immune traits showed significant associations with susceptibility of four types of pancreatitis, including AP (7 traits), AAP (8 traits), CP (14 traits), and ACP (7 traits). Twenty characteristics were found to be potential risk factors for pancreatitis, identified in B Cells (5 traits), conventional dendritic cells (cDCs, 2 traits), maturation stage of T cells (2 traits), monocytes (2 traits), myeloid cells (2 traits), T cells, B cells, natural killer cells (TBNK, 2 traits), and regulatory T cells (Treg cells, 5 traits). Multiple sensitivity analyses confirmed the validity of the findings. Meta-analysis confirmed a solid causal relationship between CX3CR1 on CD14- CD16-of monocyte panel and the susceptibility of CP.Our MR study identified immune traits causally linked to acute and chronic pancreatitis, offering new insights for early clinical intervention and immune cell-targeted therapies.Copyright © 2024 IAP and EPC. Published by Elsevier B.V. All rights reserved.