Diverticuli may be either congenital or acquired and may affect either the small or large intestines. Recently, the incidence of colonic diverticular disease is increasing in Korea but that of the small bowel, especially ileum, is very rare. We experienced a case of ileal diverticulitis causing small bowel stenosis. A 62-year-old woman was referred to our hospital because of diffuse abdominal pain for several months. Abdominal CT and small bowel series showed thickening of mucosal folds in the distal ileum. Colonoscopic findings revealed edema, mucosal thickening, blood clots, irregular dimpling, and stenosis in the distal ileum. The lesion was resected surgically and diagnosed as diverticulitis with microperforation. (Korean J Gastrointest Endosc 2004;28: 193196)