Tumors originating in the ethmoid sinuses are rare. Carcinomas of the ethmoid sinus, for example, comprise only 2–3% of all head and neck malignancies. Of this small sample, the ethmoid sinuses as the primary site varies from 5–30%. This paper presents the 14th documented case of giant cell tumor originating in the ethmoid sinuses. The pathology became the diagnostic dilemma; the case was originally diagnosed as an angiofibroma, later a reparative granuloma, and finally accepted as a giant cell tumor. The rationale for diagnosis and therapy is discussed.