A 23-year-old male presented with a 3-month history of left purulent rhinorrhea, progressive nasal obstruction, and intermittent epistaxis. A fiberoptic examination revealed a large vascular polypoid mass completely filling the left nasal cavity. CT and MRI scans showed a large hypervascular mass involving the left nasal airway, maxillary antrum, and the anterior ethmoid cells. There was no bony erosion or contiguous spread, and the remaining sinuses, orbit, and cranial fossa were uninvolved. The patient underwent complete removal of the mass via an external lateral rhinotomy approach. The soft mass was large and vascular. A microscopic analysis revealed an undifferentiated tumor consisting of a solid sheet of small, round blue cells. Mitotic figures were also present. Immunohistochemically, the tumor cells were strongly positive for CD99. Molecular studies using a PCR confirmed the chromosomal translocation of FLI1 (exon 6). These findings were considered diagnostic for Ewing's sarcoma. Postoperatively, the patient was treated with combined chemotherapy and radiotherapy. Adjuvant chemotherapy consisting of vincristine, doxorubicin, and cyclophosphamide alternating with ifosfamide and etoposide (total: 7 cycles) was commenced. He also received radiation therapy for local control (total dose: 50.4 Gy). The patient is currently alive without any evidence of recurrence or metastasis.