A 41-year-old male, with a history of neurofibromatosis type 1(NF1)was referred for further evaluation of positive fecal occult blood test. Abdominal contrast-enhanced CT incidentally showed a mass lesion with early darkening in the small intestine. It was suspected to be a small intestinal arteriovenous malformation, and surgery was performed. The tumor in the small intestine was resected under laparoscopic assistance. The histopathological diagnosis was gastrointestinal stromal tumors associated with NF1, which are usually located in the small intestine and relatively favorable prognosis.