Purpose: Primary carcinoid tumors in the duodenum are extremely rare. We present a case of a young woman with a large duodenal carcinoid tumor that involved rare location in the fourth portion of duodenum with no further evidence of disease who presented with acute and chronic gastrointestinal bleeding. Case report: 44 year old woman with history of chronic hypertension, hypertensive encephalopathy, end-stage renal disease on outpatient hemodialysis and diagnosis of severe refractory anemia presented from dialysis center with fever. Next day she had blood clots in the stool. She denied abdominal pain, flushing, nausea, vomiting, chest pain, cough, dyspnea, arthralgia, diarrhea or similar bleeding episodes in the past. On examination she was febrile, orthostatic and pale. Her abdomen was soft and nontender with no palpable masses or enlarged organs. Blood was present on digital rectal exam. Her hemoglobin dropped from 10.8 mg/dL to 7.9 gm/dL in one day and she was transfused blood. Her BUN level was 57 mg/dL, creatinine 10.4 mg/dL. She had an emergent colonoscopy which showed internal hemorrhoids. On esophagogastroduodenoscopy (EGD) esophagus, stomach, duodenal bulb, descending duodenum appeared healthy. Fresh blood was seen distal to the ampulla of Vater and a large 5 cm raised, ulcerated mass lesion was seen in the fourth portion of the duodenum suspicious of malignancy. The lesion occupied almost half of the lumen but was nonobstructing. The biopsy showed carcinoid tumor positive for Neuron-specific Enolase, Chromogranin and Synaptophysin. She had CT scan of the abdomen, pelvis and chest, and bone scan which did not show metastasis. Her Chromogranin A level was 613 ng/ml. Discussion: Duodenal carcinoids are rare tumors and incidence varies from 1–3% of all duodenal tumors and 2.6% of carcinoid tumors in US. These tumors are generally 0.5–2 cms in size, occur mostly in the proximal part of the duodenum or periampullary region and are occasionally associated with carcinoid syndrome. Erosion of duodenal carcinoid producing hemorrhage is a rare occurrence. This case is a unique presentation of erosion of a 5 cm duodenal carcinoid present in distal duodenum leading to an acute gastrointestinal blood loss superimposed on chronic low grade blood loss misconstrued as ‘refractory anemia’. Despite the large size of the tumor there was no metastasis to the liver.