Case histories of 10 patients with neurofibrosarcoma, including 14 (70%) with neurofibromatosis, evaluated over 10 years were reviewed to determine the incidence of local and systemic recurrence and the most effective means of therapy for this rare neoplasm. Initial therapy resulted in complete local disease control in only 11 (55%) patients. Local excision, or local excision plus radiation or chemotherapy resulted in local recurrence in 8 of 12 patients. Radical surgery alone, or radical surgery combined with radiation and chemotherapy resulted in local recurrence in 1 of 6. Even with complete local disease control, 7 of 16 (44%) patients died of metastases. Both A.J.C. Clinical Stage II and III patients had a similar poor prognosis. Associated neurofibromatosis did not worsen prognosis. These data suggest that both moderate and high-grade primary neurofibrosarcoma are highly malignant neoplasms and should be treated by radical resection. Preoperative intraarterial Adriamycin and radiation--found to be successful for other highly malignant sarcomas--may be of benefit. Since distant disease occurs despite local control, postoperative adjuvant chemotherapy trials are warranted.