Introduction: Amyloidosis is a group of diseases caused by abnormal deposition of insoluble amyloid fi brils in various tissues of the body. Diagnosis of gastrointestinal amyloidosis is difficult by reason of various symptoms and nonspecific endoscopic fi ndings. Here, we report a case of small and large intestine amyloidosis in multiple myeloma appeared as ischemic colitis. Case Report: A 67-year-old female was admitted due to hematochezia with abdominal pain. Immediate lower gastrointestinal endoscopy was done and showed necrotic colonic mucosa on transverse colon (fig. 1 A). Contrast-enhanced computed tomography revealed ischemic colitis with intramural hematoma (fig. 1 B). Thus,she had emergency right hemicolectomy for necrotizing ischemic colitis. After operation, she took ordinary postoperative care and discharged. After 1 month, she was admitted again due to abdominal pain and melena. There was no evidence of bleeding on upper gastrointestinal endoscopy. Lower gastrointestinal endoscopy revealed multiple ulcer of various size and shape in distal ileum and biopsy was done (fig. 1 C). Histopathologic exam exhibited green birefringence under polarized light microscopy (fig. 1 D). Therefore we could diagnose ileal amyloidosis. We reviewed surgically resected colonic tissue and had same result. Additional test, serum and urine protein electrophoresis, provided clues to multiple myeloma. Subseqent bone marrow biopsy confi rmed multiple myeloma. finally, we diagnosed intestinal amyloidosis in multiple myeloma which presented as necrotizing ischemic colitis. She took chemotherapy for multiple myeloma in oncology and has improved gradually until now 18 month after diagnosis. Conclusion: We report a case of a small and large intestinal amyloidosis fi rst presented with hematochezia and abdominal pain as typical ischemic colitis and showed necrotizing ischemic colitis in endoscopy. Gastroenterologist and endoscopist have to be aware of possibility of intestinal amyloidosis in case of ischemic colitis. Key word: Amyloidosis, Ischemic colitis, Hematochezia, Endoscopy.