Crohn's disease can involve any portion of the digestive tract, but isolated gastric Crohn's disease is a rare entity. In the few previously reported cases, the inflammatory disorder has involved only a portion of the stomach. Herein we describe a patient with diffuse involvement of the entire stomach and an associated gastrosplenic fistula but no evidence of involvement elsewhere in the gastrointestinal tract. Usually, a patient with isolated Crohn's disease of the stomach will have the clinical symptoms of nausea, vomiting, and epigastric pain and radiographic evidence of a small contracted stomach (or, occasionally, a huge dilated stomach). Because the condition may suggest the presence of a malignant lesion and biopsy specimens often reveal nonspecific inflammation, surgical resection is usually necessary for diagnosis of isolated Crohn's disease of the stomach.