This paper presents a state-of-the-art review of using mobilized-peripheral blood progenitor cells (PBPC) for transplantation in children. Our own data and those from Medline searches and meeting reports, are analyzed and presented for the different sections that involve transplantation. Recommendations concerning the choice of mobilization regimens, venous access, priming of separator extracorporeal line, anticoagulation, and number of CD34+ cells to infuse for rapid engraftment are proposed. In the allogeneic setting, we analyze ethical and safety aspects of pediatric donor mobilization and collection. Data from the literature suggest that the use of cytokine-mobilized PBPC for allogeneic transplantation appears to be safe both for pediatric donors and patients leading a rapid hematopoietic engraftment with a similar incidence of acute graft-versus-host disease (GVHD). The high incidence of chronic GVHD and its management emerge as the most concerning aspect in allogeneic PBPC transplantation.