Malignant gastointestinal stromal tumors (M-GIST ) are rare mesenchymal tumors that arise in the wall of the gastrointestinal (GI) tract. Small intestinal GIST account for approximately 35% of all GIST; the diagnosis of these tumors is difficult to establish, because the symptoms are vague and non-specific and traditional endoscopy is commonly unsatisfactory. Because of the infrequent nature of malignant small bowel tumors, the natural history and factors affecting outcome remain poorly defined; stage at presentation and complete surgical resection seem to be the main prognostic factors. For these rare tumors, surgery remains the treatment of choice, with little efficacy reported for irradiation, chemiotherapy, or both. Two cases of GIST of the jejunum, complicated by intestinal bleeding and intestinal obstruction respectively, are presented and a review of the literature is made.