Disclosure All authors disclosed no financial relationships relative to the content of this work. Commentary Immune checkpoint inhibitors are monoclonal antibodies that block binding between programmed cell death receptors on activated T cells and programmed cell death ligand-1 on target tissue. This leads to high cytotoxicity and secretion of pro-inflammatory cytokines that clear tumor cells by the immune system. Immunotherapy has become a game changer for the treatment of many cancers. Inasmuch as this type of therapy is used more frequently, we are encountering more adverse effects related to immunotherapy, including immune-mediated gastritis. The symptoms of immune-mediated gastritis include epigastric and abdominal pain, nausea, vomiting, anorexia, weight loss, bloating, diarrhea, hematemesis, and melena. Endoscopically, immune-mediated gastritis often presents as an erosive fibrinous pangastritis with solid white exudate, sloughing of the gastric mucosa, and edematous and friable mucosa with hemorrhagic gastritis. Additionally, there is relative endoscopic sparing of the esophagus and duodenal mucosa. Histologic analysis demonstrates destruction of the gastric mucosa and mucosal glands, loss of parietal cells in the gastric body, granulation tissue, marked neutrophilic and lymphocytic cell infiltrate, microabscesses, and the relative preservation of the muscularis mucosa and submucosa. Viral testing excludes cytomegalovirus and herpes simplex virus, and a test result for Helicobacter pylori is also negative. Labaratory evaluation typically demonstrates very low gastric levels and negative antiparietal cell and anti-intrinsic factor antibodies, dismissing autoimmune gastritis. Treatment typically involves steroids and proton pump inhibitors. Here, the authors present a case of immunotherapy-induced gastritis successfully managed with cessation of the offending agent, pembrolizumab, and initiation of steroids, proton pump inhibitors, and sucralfate. Courtney Walker, DO, Department of Gastroenterology, St Charles Medical Center, Bend, Oregon, USA Amy Tyberg, MD, FASGE, FACG, Associate Editor for Focal Points