Background: Gastrointestinal stromal tumors (GISTs) are low-grade malignant tumors that may arise anywhere in the alimentary tract, and in the past, most of them were diagnosed as intestinal leiomyoma or leiomyosarcoma. GISTs of the duodenum make up only 4.5% of all GISTs. Materials and Methods: We report a patient presented with upper GI bleeding who exhibited radiological findings of a tumor in the third portion of the duodenum. The patient underwent a segmental duodenectomy. Pathological examination concluded in a GIST. Results: The patient is free of recurrence for one year after surgery. Conclusions: Our case report, along with other, highlights that surgical resection remains the cornerstone of treatment for patients with localized disease. Along with others, we agree that from oncologic point of view, partial resection of the duodenum is an alternative to a duodenopancreatectomy.