Ménétrier's disease is a rare premalignant disorder of the stomach with no proven effective medical therapy. Increased epidermal growth factor receptor signaling has been implicated in the pathogenesis of Ménétrier's disease. We conducted a single-arm clinical trial with cetuximab, a monoclonal antibody that blocks epidermal growth factor receptor signaling, in nine individuals with clinically and histologically documented severe Ménétrier's disease that impaired quality of life to the extent that gastrectomy was being considered. Of the seven patients who completed the 1-month course of treatment, all showed statistically significant improvement both clinically (quality-of-life indices) and biochemically (increased parietal cell mass and gastric acidity). Furthermore, all seven patients who completed the 1-month trial elected to continue treatment, and four subsequently showed near-complete histological remission. Cetuximab should be considered as first-line therapy for Ménétrier's disease.