Ischemic colitis is the most common vascular disorder of intestines, and usually affects older patients. Many predisposing conditions have been implicated in the pathogenesis of colonic ischemia, although many occurrences are spontaneous in nature. Ischemic colitis can induce a wide spectrum of radiological or endoscopic features, depending on the site, extend, and timing of its onset. The coexistence of colonic ischemia with carcinoma of large bowel is well documented. However It is less well recognized that a localized segment of ischemic colon can mimic a carcinoma. Here, we report a case of ischemic colitis mimicking colon cancer in a 66 year-old man. (Korean J Gastrointest Endosc 2004;29:4145)