The experience with the treatment of malignant histiocytosis has been disappointing. Despite modest treatment success with a combination of cyclophosphamide, Adriamycin (doxorubicin), vincristine and prednisone, the overall prognosis remains poor. There are only a few reports of prolonged complete remissions in pediatric patients. The following report describes two children who have had long-term remission with an aggressive combination chemotherapy program that included intrathecal prophylaxis. The chemotherapeutic regimen described merits further evaluation in a larger number of patients.