The authors report two cases of small bowel malignant schwannoma. It is an extremely rare disease and it is often difficult to diagnose malignancy. Histologic differentiation from other stromal tumors may require electron microscopy, although the preparation of immunohistochemical reactions now allows to identify forms which were previously diagnosed in different terms to be precisely classified. Diagnosis is often late and no preoperative test enables a correct clinical diagnosis to be made. The primary treatment is surgical and the resection is the only real therapy. Radiotherapy and chemotherapy are ineffective. Close postoperative observation is recommended because of the tendency to recurrence and metastasis.