Carcinoma of the cystic duct remnant is extremely rare, and only five cases have been reported previously in the English literature. We present another case of carcinoma of the cystic duct remnant and review the literature. A 62-yr-old woman was diagnosed as having hilar cholangiocarcinoma and transverse colon cancer. However, at laparotomy, the center of the tumor mass was in the cystic duct remnant with contiguous colonic invasion. The pathology of the surgical specimen confirmed carcinoma of the cystic duct remnant. The diagnosis of carcinoma of the cystic duct remnant was made using Ozden's new criteria.