Primary or secondary melanoma of the small intestine is rare. Here, we present a case of a 57-year-old female patient with melena and microcytic anemia. Computed tomography (CT) showed a submucosal tumor of the duodenum, the circumferential thickening of the jejunum wall, and multiple simultaneous small bowel intussusceptions without significant bowel obstruction. Endoscopy showed a pigmented submucosal tumor in the duodenum. Malignant melanoma was confirmed through biopsy. There was no definitely identifiable cutaneous lesion.