Dieulafoy's vascular malformation is a rare cause of massive gastrointestinal bleeding. Most often it occurs in stomach within 6 cm from the gastroesophageal junction. Only a few cases have been reported to occur in the small intestine and colon. Occasionally, Dieulafoy's lesion of small intestine is difficult to recognize because of rarity, a paucity of symptoms and negative findings on barium studies. Therefore, this lesion needs to be considered in a patient with massive lower gastrointestinal bleeding. We report a case of Dieulafoy's vascular malformation in ileum 2 m proximal to ileocecal value in a 41-year-old woman who visited emergency clinic because of hematemesis, dizziness and vomiting. Small intestine revealed a wide-caliber artery within the submucosa showing intimal thickening, medial muscular hypertrophy and thrombosis.