INTRODUCTION: Gastrointestinal stromal tumors are the most frequent (0,5-3%) mesenchymal tumors in the gastrointestinal tract. They probably originate from the interstitial cells of Cajal and are characterized by an anomaly of c-kit receptor, for a stem growth factor, with tyrosine-kinase activity (c-kit). This mutation causes a permanent activation of the receptor and uncontrolled cell growth. These tumors are associated with low survival in cases of advanced or metastatic disease. Imatinib, a tyrosine kinase inhibitor, induces improved survival in these patients. CASE REPORTS: The authors discuss two cases of gastrointestinal stromal tumors surgically treated and also review the pathophysiology, diagnosis difficulties, role of surgery today, and treatment-related outcome of this type of tumors.