The aim of our single center pilot study was to evaluate the feasibility of peripheral blood stem cell autotransplantation (PBSCT) in a pediatric population. Only children with solid and hematological malignancies and poor prognosis who were without a HLA-identical bone marrow donor were included in this study. Mobilization of PBSC was done by treatment with myelosuppressive chemotherapy followed by recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF). Circulating progenitor cells were harvested by a total of 24 leukaphereses on an AS 104 cell separator in eight patients. Seven patients had undergone conditioning with high-dose chemotherapy with or without irradiation prior to PBSCT. All patients showed a rapid hematological recovery, although reconstitution of thrombopoiesis was incomplete in three children. We conclude that PBSCT is feasible in childhood and that it results in a rapid hematologic recovery.