Extraskeletal Ewing's sarcoma is rarely found arising in the head and neck region. Only six cases of extraskeletal Ewing's sarcoma invading the nasal cavity or paranasal sinuses have been reported in the literature. The first described case of that Ewing's sarcoma located in isolated maxillary sinus extending into the orbita without involving the nose is presented. A 16-year-old woman presented with swelling in her right cheek. The nasal examination was normal. A computed tomography (CT) and magnetic resonance imaging (MRI) of the sinuses revealed a large mass in the right maxillary sinus with extension to the orbita. Under general anesthesia biopsies were taken. Based on histopathological analysis, a diagnosis of extraskeletal Ewing's sarcoma was made. The patient did not accept the surgical therapy. The patient was treated with combined chemotherapy and radiotherapy. The patient has done without evidence of recurrence or metastasis for one year.