Granulocytic sarcomas are rare extramedullary tumors of malignant myeloid precursor cells. Exceedingly rare in childhood, it commonly involves skin, lymph nodes, bone, and the spine. Ovarian involvement is rare. It can arise de novo, precede the development of acute nonlymphocytic leukemia, or be the sole manifestation of relapse. We describe a 26-year-old woman with granulocytic sarcoma of the ovary without any hematologic disorder.