We successfully treated a 22-year-old woman with eosinophilic gastroenteritis (EGE) using a multiple food-elimination diet. The patient was diagnosed with EGE based on histopathological findings and initially treated with oral prednisolone. The symptoms immediately improved, although they recurred when prednisolone was tapered to a low dose. We then treated her with a multiple food-elimination diet, including milk, soy, eggs, wheat, nuts, seafood, and rice. During dietary treatment, we identified dairy products and eggs as causative foods of the symptoms, and we ceased prednisolone. Similar to eosinophilic esophagitis, an elimination diet may be effective for adult patients with EGE.