Objective: Gastrointestinal stromal tumors (GIST), most commonly occur sporadically, but there seens to be some increased tendency for these tumors to develop in patients with neurofi-bromatosis1(NF1). There is no histological difference between the NF1 assocaciated cases and the sporadic cases. However, tumors associated with NF1 frequently show multiplicity. Method: A case of multiple duodenal gastrointestinal tumor arising in a 45 year old mal with NF1 is reported. The abdominal exploration revealed multiple solid nodules in the duodenum, and the pancretecticoduodenectomy was performed.