Dieulafoy's lesions are often unrecognized cause of obscure, massive gastrointestinal bleeding, reported to be 0.3~1.5% of cases of major gastrointestinal bleeding. It is characterized by severe bleeding from rupture of an exposed submucosal artery. Dieulafoy's lesion is usually occured in the lesser curvature of the stomach within 6 cm of the gastroesophageal junction. Similar lesions have also been described in the esophagus, duodenum, small intestine, colon, and rectum. The diagnosis is made by endoscopy, angiography, laparoscopy, or laparotomy. Endoscopy showed protruding and eroded artery with pulsatile bleeding or adherent thrombus. Currently, various therapeutic options are available to the endoscopist for the treatment of Dieulafoy's lesions. Therapeutic endoscopy should now become first-line therapy for Dieulafoy's lesions. We experienced a rare case of bleeding from the duodenal Dieulafoy's lesion. Endoscopic hemoclipping was performed successfully. We report this case with a review of the literature.