Iron deficiency anemia and hypoproteinemia occur commonly in patients with Crohn's disease. They invariably have other clinical manifestations, principally abdominal pain, diarrhea and weight loss. However, severe anemia and hypoproteinemia as the sole presentation without any other clinical evidence to suggest Crohn's disease is extremely uncommon and raises a diagnostic problem. A 31-year-old man presented with generalized edema and dyspnea on exertion without any significant gastrointestinal symptoms. Hemoglobin level was 3.8 g/dL, and serum protein and albumin levels were 3.5 g/dL and 1.2 g/dL, respectively. Urinalysis finding was normal, and fecal clearance of α-1 antitrypsin increased markedly up to 873 mL/24 hr, suggesting severe protein loss through the gastrointestinal tract. A CT scan and small bowel barium study revealed lesions in the jejunum. Surgical resection corrected his problems, and pathological examination of the specimen proved to be Crohn's disease. (Korean J Gastroenterol 2002;39:128-132)