SummaryTumour necrosis factor‐related apoptosis‐inducing ligand (TRAIL) and its receptor (TRAIL‐R) play important roles in immune regulation and cancer cell death. Although TRAIL has been shown to induce chemokine release in various tumour cells, the function of TRAIL‐R in the development of colitis and colitis‐associated carcinogenesis has not been explored. In this study, we found that TRAIL‐R‐deficient mice exhibited a higher incidence of colitis and colitis‐associated cancer than that of wild‐type (WT) mice, and TRAIL‐R expression was down‐regulated in WT mice that were fed dextran sulphate sodium. Chemokines, including CCL2 and CXCL1, were highly expressed in the serum and inflammatory colon tissues of TRAIL‐R−/− mice compared with WT mice, and TRAIL‐R−/− mice showed a marked infiltration of immune cells during colitis. Hyperactivation of Janus kinase and nuclear factor‐κB in colon epithelial cells was also observed, which correlated with the severity of colonic inflammation in TRAIL‐R−/− mice. These data suggest that TRAIL‐R plays a protective role in chemical‐induced colon injury and negatively regulates mucosal immune responses.