Currently, granulocyte colony stimulating factor (G-CSF) alone or in combination with myelosuppresive chemotherapy remain the standards of CD34+ cells mobilization allows the safe and successful collection of adequate peripheral blood stem cells (PBSC) for autologous transplantation. However, in up to 30% of patients mobilization of PBSC is ineffective. This report presents our experience in mobilization and collection of peripheral blood stem cells in 82 children with different proliferative disease. In mobilization G-CSF was administered alone in steady state (56 patients, pts) or in combination with myelosuppresive chemotherapy (26 pts). The CD34+ cell count at least 10 cells/ml was required to start apheresis procedure, which was repeated, if needed, during following 1-4 days until collection of at least 2 (optimally 3) x106 CD34+ cells/kg b.w. of recipient was obtained. Three pts in each group (3/ 56 and 3/26) failed the first course of mobilization. The median number of CD34+ cells mobilized was 4.8 (0.5-15) x106/kg b.w. The minimal and optimal number of CD34+ cells for transplantation was achieved in 85% and 61% of patients in the G-CSF + chemotherapy group and in 84% and 54% in the G-CSF group, respectively. The efficacy of presented mobilization arms in our group was similar. However, the incidence of infection and total hospitalization time during mobilization were higher in chemotherapy + G-CSF group.