Juvenile ossifying fibroma - report of two cases. OBJECTIVE: To describe two cases of juvenile ossifying fibroma (FOJ), one of them atypical location, operated in the Santa Casa of Belo Horizonte. CASE REPORT: First male patient, five years, had a history of intermittent bilateral epistaxis for a week with no other complaints, co morbidities or allergies. On examination, tumor, bleeding to the touch, blocking the nasal passages. Sphenoidal tomography revealed a mass with intracranial extension, causing displacement of the intracavernous carotid, chiasm and optic nerves, and invasion of the middle tank. Biopsy showed FOJ. Surgery was performed with endoscopic resection of the lesion without signs of recurrence after one year. Second, male patient, eight years, started with a lesion in the right maxillary region for a year and four months. Underwent resection, evolving, after nine months, with recurrence. Had hardened mass in the right maxilla, causing protrusion of the anterior maxilla, the nasal septum and hard palate. Computerized Tomography showed a tumor with radiopaque areas occupying the right maxillary sinus, nasal cavity, hard palate, and floor of the orbit. Biopsy revealed FOJ. Surgically treated with total maxillectomy, had an uneventful postoperative course. CONCLUSION: The FOJ is a rare benign tumor, locally aggressive and recurrent that primarily affects the craniofacial skeleton, most commonly jaw, jaw and sinuses of young individuals. The occurrence in the sphenoid sinus is rarely described. This report provides a brief literature review and discusses histological types, location, differential diagnosis and therapeutic possibilities for this condition.