Gastrointestinal stromal tumors (GIST) are the most common mesenchymal neoplasms, accounting for 1% to 2% of all malignancies of the digestive tract. Gastrointestinal stromal tumors are rare mesenchymal tumors (0.1% to 3% of all malignant gastrointestinal tumors) that originate within the interstitial cells of Cajal. We present a case of an 83-yearold patient with melena and hematochezia of one week's duration with hemodynamic instability. Complete resection with laparotomy and embolization of the 5 x 3.5 cm GIST was performed. The histopathology report showed spindle cells, a low mitotic index and the immunohistochemistry report: DOG-1+/CD117+/ H.CALDESMON + FOCAL. Treatment with imatinib is started. In this case report we describe the clinical presentation, diagnosis and treatment of gastric stromal tumor.