Three children with acquired immunodeficiency syndrome (AIDS) and chronic anaemia and leucopenia were treated with 5 micrograms/kg recombinant granulocyte colony-stimulating factor subcutaneously three times a week and 50 IU/kg erythropoietin subcutaneously twice a week. The therapy was not interrupted during the follow-up period. All children showed an increase of leukocyte count and haemoglobin levels. No transfusion was necessary and the number of admissions into hospital fell. These results suggest that combined therapy with granulocyte colony-stimulating factor and erythropoietin may improve leukopenia and anaemia, which is not zidovudine-related, in children who have AIDS.