Malignant duodenocolic fistula is a seldom-seen complication of advanced right colon carcinoma. We describe four patients who illustrate the sometimes rewarding results of aggressive treatment. Because duodenocolic fistula is always associated with severe nutritional impairment, operation should be deferred until total parenteral nutrition (TPN) and blood transfusions have improved the clinical state. Whenever feasible, resection offers the best treatment; lesser techniques such as bypass and exclusion result only in minimal palliation. A direct approach and fistula disconnection are contraindicated. The benefit of exploration should almost always be offered, even in such secondary fistulas, as a better quality of life and long-term survival are realistic goals.