The authors report a case of a 13-year-old female with recurrent Burkitt lymphoma who was heavily pretreated with chemotherapy. During chemotherapy for relapse, she developed serious aspergillus infection of the palate and sinuses. Despite 10 microg/kg of filgrastim for 5 days, peripheral blood CD34(+) cells remained <or=1/microL. Hematopoietic progenitor cells were subsequently successfully mobilized with a combination of AMD3100 and filgrastim without tumor or fungus contamination. After transplantation, the patient achieved complete engraftment without exacerbation of fungal infection. This is the first case report of a pediatric patient with relapsed Burkitt lymphoma with mobilization of hematopoietic progenitor cells by AMD3100 without any adverse reactions.