We report the clinical and laboratory features of a 19-year-old man with findings of both eosinophilic gastroenteritis and gluten-sensitive enteropathy. Before the onset of clinical symptoms, the patient had received a series of hepatitis B vaccinations but had not developed a measurable antibody response or any allergic reaction. Radioallergosorbent test results were positive to several foods, and the total serum immunoglobulin E (IgE) level was elevated. Adherence to a gluten-free diet caused a normalization in the endomysial antibody titer; however, the total serum IgE level continued to increase, and the total eosinophil count remained elevated. Symptoms of recurrent vomiting and abdominal pain necessitated prednisone burst therapy. The simultaneous occurrence of eosinophilic gastroenteritis and gluten-sensitive enteropathy is rare; therapy should be directed to each disorder individually.