Granulocytic sarcoma is an extramedullary tumor composed of immature granulocytic precursor cells. It usually occurs in association with leukemia or other myeloproliferative disorders but can occur without overt hematologic disease. We describe a 6-year-old boy with granulocytic sarcoma in the absence of demonstrable hematologic disease and review the literature regarding the diagnosis, clinical associations, and treatment of this condition.