Imaging of terminal ileitis in a 80-year-old male with metastatic melanoma treated with nivolumab and history of inflammatory bowel disease (IBD). After 6 month of therapy, the patient presented abdominal distension and constipation. Axial CECT showed concentric wall thickening and mucosal hyperenhancement of the last ileal loop (white arrowheads in A, B and C) with some enlarged lymph node in the adjacent colonic fat (white arrows in A, B and C). Colonoscopy with biopsy was performed and histology showed a “terminal ileitis and intense chronic follicular inflammation associated with tiny ulcers, compatible with IBD”. Immunotherapy was not discontinued and the patient started a specific treatment for IBD. After 3 months, symptoms regressed and CECT showed a complete regression of the terminal ileitis (white arrows in D and E).