Primary sclerosing cholangitis (PSC) is chronic liver disease characterized by inflammation and fibrosis of small and large bile ducts commonly associated with inflammatory bowel disease (IBD). MAIT cells are abundant in the human liver and have been shown to locate around bile ducts. Interestingly biliary epithelial cells can present antigen via MR1 and activate MAIT cells. However, the role of MAIT cells in PSC remains unclear. We used PBMCs to characterize MAIT cells in PSC patients comparing them to healthy individuals and patients with IBD and primary biliary cholangitis (PBC) as controls. In a first step we noted a reduced MAIT cell frequency in PSC patients, as well as in diseased controls, compared to healthy individuals with preferential loss of CD8+ MAIT cells. Further phenotypical analysis showed a slight increase in the expression of activation markers in PSC patients and reduced expression of CXCR6+ as compared to healthy individuals. In contrast, diseased controls exhibited a more activated phenotype. In line with the noted phenotypic alterations, MAIT cell function was reduced in response to E.coli or cytokine stimulation in both PSC and IBD patients whereas PBC disease controls presented with intact function. Finally, when investigating whether MAIT cells localized to bile ducts during PSC, we noted a tenfold increase in the number of the MAIT cells residing in PSC patient bile ducts compared to controls. These findings suggest a redistribution of functionally impaired MAIT cells to the compartment affected by chronic inflammation in PSC.