OBJECTIVE: To report a case of polyostotic fibrous dysplasia treated at the Department of Otolaryngology and Facial Surgery Regional Hospital Presidente Prudente-SP in 2012. Summary: VGSA, 2 years and 9 months, brown, natural Presidente Epitácio - SP, was referred to the Department of Otolaryngology in April 2012. The patient presented so that doctors could assess a nodule located about 2 cm between the maxillary and nasal wing right for 2 months with progressive growth accompanied by local pain, nasal obstruction, absence of fever, or weight loss. The patient's medical history included report of a mass in the distal region of the right femur with suspected fibrous dysplasia. A CT of the sinuses revealed a solid nodular lesion adjacent to the right nasal septum. We sought to determine the effect of this atrophic pressure on nearby bony areas. The adjacent bony area measuring 21 mm × 20 mm. Changes in the bony structures of the face indicated right expansion, swelling, and severe sclerosis, with ground-glass, calvarial areas with similar characteristics most evident on the right side and involving mainly the regions of the spinal bones. The lesion in the right maxillary sinus was removed to alleviate the patient's symptoms. The results of the pathology analysis were consistent with fibrous dysplasia. CONCLUSION: Fibrous dysplasia is a benign disease of unknown etiology characterized by a bone disorder where normal bone becomes fibrous, disorganized, trabecular tissue. The bones most affected in descending order are the frontal, sphenoid, ethmoid, parietal, temporal, and occipital bones, with the jaw affected only rarely. The patient underwent successful surgical treatment and is currently in regular outpatient treatment.