Although inflammatory polyposis of the colon is a recognized local complication of ulcerative colitis, giant inflammatory polyposis that totally obliterates the colonic lumen is uncommon, and most of the patients have been from Western countries. We report a Japanese man who had localized giant inflammatory polyposis that obstructed the retrograde flow of barium in a double-contrast barium enema study at the splenic flexure in ulcerative colitis. After resection by total proctocolectomy and ileostomy, pathological examination of the specimen confirmed localized giant inflammatory polyposis in the descending colon and spelnic flexure without malignancy.