Extramedullary myeloid cell tumors are discrete tissue infiltrations by leukemic cells of myeloid lineage. They are more commonly associated with relapsing acute myelogenous leukemia but can occur in myeloproliferative/myelodysplastic leukemia, usually associated with disease acceleration. Although they can occur in any organ, reported testicular infiltration is rare. We describe the clinical presentation of an extramedullary myeloid cell tumor as a unilateral testicular mass in a man with known chronic myelomonocytic leukemia and its histologic diagnosis. To our knowledge, this manner of presentation is unique in this clinical context.