The use of recombinant human granulocyte-stimulating factor (G-CSF) has been shown to effectively accelerate granulocytic recovery after autologous bone marrow transplantation (BMT) in adults. The experience, however, is limited in children. We evaluated the hematopoietic reconstitution in 41 consecutive children undergoing autologous BMT for hematologic malignancies (21 acute lymphoblastic leukemia, five non-Hodgkin's lymphoma) and solid tumours (seven neuroblastoma, two brain tumor, three Ewing's sarcoma, two Wilms' tumor, one rhabdomyosarcoma). Their ages ranged from 2 to 16 years (mean 7.2 years). rhG-CSF was given at a dose of 10 micrograms/kg/day i.v. in a 2h infusion from day +1 until +28 or until the absolute neutrophil count (ANC) was > 1 x 10(9)/L. These patients were compared with a similar historical control group of 38 children who did not receive rhG-CSF after autologous BMT. The number of cells infused was similar in both groups. At the dose and schedule used in the present study, rhG-CSF was well tolerated and no side-effects were observed. The number of cell infused was similar in both groups. At the dose and schedule used in the present study, rhG-CSF was well tolerated and no side-effects were observed. Our data show that rhG-CSF accelerates engraftment and reduces the number of febrile days and antibiotic use. Furthermore, patients who were treated had less infections.