Introduction: The coexistence of synchronic duodenal gastrointestinal stromal tumor (GIST) and neuroendocrine tumor in a patient with neurofibromatosis type 1 (NF1) is extremely rare, and only eight cases were described in the literature. Clinical Case: This is a rare case of a 38-year-old female patient with NF1 who developed synchronic GIST and neuroendocrine tumor, which were both in the second portion of the duodenum. The first symptoms were abrupt digestive bleeding and anemia. Upper digestive endoscopy revealed two tumors, sizes 2.5 and 3.0 cm, in the second portion of duodenum, with biopsies identifying a GIST and a neuroendocrine tumor. Therapeutic decision was to proceed to surgical resection, and Whipple's procedure was indicated. Surgical procedure was performed with good outcome. Currently the patient has excellent quality of life and maintains follow up for thirty months without recurrence. Discussion: Long-term disease-free survival and excellent quality of life are reported when these tumors are fully resected in this context. However, it is not always easy to access the gastrointestinal tract, especially the small intestine, and proceed to the histopathologic diagnosis of these tumors. Conclusion: It is important to be aware of the possibility of the coexistence of various tumors in the NF1 scenario for adequate screening, staging, and surgical treatment of these patients, as good prognosis can be achieved when such tumors are detected and treated properly.