Primary malignant schwannoma of the small and large intestine is an extremely rare disease. Therefore, we are going to report an aggressive multifocal malignant intestinal schwannoma in a 66-year old female patient, that was primarily diagnosed as the gynecological tumor that, even after the surgical treatment, had a very quickly recurrence. Small intestine tumors may show images similar to an adnexal tumor, so it is difficult to differentiate one from another prior to the surgery. The patient did not suffer from neurofibromatosis type 1 (NF-1), disease that increases occurrence of malignant schwannoma in comparison with general population. These tumors are often diagnosed late, and radical surgical intervention does not guarantee longer survival. After surgical removal of macroscopically visible tumor masses from this patient, tumor formation within one month after the operation had reached the sizes of 83x66 mm and 85x75 mmrespectively, with the occurrence of metastases in the liver, and thereafter the patient died. In differential diagnosis of adnexal tumor small intestine tumor has to be considered, especially if nonspecific symptoms are present
