Neurofibromatosis type 1(NF-1) with gastrointestinal stromal tumor (GIST) is a rare case in clinical practice. But it is even rarer that the GIST tumor in this case is so large that it cause small intestinal obstruction. Here we report such a male case of NF-1,with positive family history of NF-1 and nodules all over the patient's skin and abdominal cavity. The patient came to hospital with a sudden upper abdominal pain and nausea and vomiting over 5 d. Abdominal computerized tomography (CT) showed that there were numerous nodules of different size in his abdominal cavity. And the largest one is about 10 cm in diameter,which oppressed the small bowel and caused the small bowel mesenteric volvulus and obstruction of the bowel. Finally,the tumor was pathologically proved to be a GIST tumor but not NF nodule. The patient stays healthy until now after operation.