Thirty-two children with malignant histiocytosis were managed at the Department of Pediatrics of the Gustave-Roussy Institute from January 1975 through December 1987. Clinical presentation included enlarged lymph nodes in all cases, a decline in general health with fever in 74%, skin manifestations in 54%, and visceral involvement in 55%. Twenty-seven patients were treated with the COPAD protocol combining vincristine, cyclophosphamide, adriamycin and prednisone. Twenty-two patients achieved a complete remission, and one a partial remission; there was no remission in four patients. Eight patients had a recurrence and were given a combination of CCNU, vinblastine and bleomycin; seven achieved a second complete remission. Overall survival rate was 72.2% with a median follow up of five years. Survival rate free of disease was 54.5%. Poor prognostic factors included presence of constitutional symptoms upon diagnosis and age under ten years.