Thirty-nine chemotherapy trials in 16 patients with metastatic hemangiopericytoma treated at MSKCC and 33 trials from the literature are reviewed. Adriamycin, alone or in combination drug regimens, is the most effective agent, producing complete and partial remission in 50% of cases. Other drugs which show some activity include vincristine, cyclophosphamide, actinomycin, methotrexate and DTIC. The available data indicate malignant hemangiopericytoma should be considered chemotherapeutically responsive tumors.