A 54-year-old man presented to our department with abdominal discomfort and anorexia and was diagnosed as having Ménétrier's disease (MD) with hilar cholangiocarcinoma. Based on his clinical examination, there was no evidence of Helicobacter pylori or cytomegalovirus (CMV) infection. Although we administered proton pump inhibitor and high-calorie enteral nutrition, hypoproteinemia did not improve, and the refractory protein-losing enteropathy persisted. However, interestingly, MD improved immediately after resection of the hilar cholangiocarcinoma. Generally, the etiology of MD is unknown, but H. pylori and CMV infections have been implicated. To our knowledge, there has been no previous report indicating that a malignant tumor could be involved in the etiology of MD. Thus, we report an extremely rare case of MD which is seemingly caused by malignancy.