We describe the case of a 65-year-old woman who presented with left nasal obstruction. Clinical and radiographic examinations revealed the presence of a soft-tissue mass that had obliterated the left nasal cavity. The mass was completely excised via an endoscopic approach. Histopathologic examination identified the tumor as an ossifying fibrosarcoma. The patient recovered uneventfully and remained free of disease at the 2-year postoperative follow-up. To the best of our knowledge, no case of an ossifying fibrosarcoma of the nasal cavity has been previously reported in the English-language literature. We discuss the features of this case and the clinical presentation, diagnosis, and management of fibrosarcomas of the nasal cavity and paranasal sinuses.