Abstract A case of an 11-year-old female with cementifying fibroma in the ethmoidal sinus extending to the anterior cranial base was presented. She complained of slowly progressive nasal obstruction and anosmia. Magnetic resonance imaging (MRI) revealed a tumor in both ethmoidal and sphenoidal sinuses and nasal cavity. Although a tumor reduction surgery was attempted through a transnasal approach, tumor size increased gradually and right exophthalmos subsequently appeared. The pathological diagnosis was cementifying fibroma of the nose. Total tumor removal was consequently accomplished through the intracranial anterior transbasal approach. The surgical approach should be selected according to the site and expansion of the lesion in individual patients.