Giant cell reparative granuloma (GCRG) is a rare benign tumor that develops in the first two decades of life. Data on the incidence of GCRG in children vary significantly depending on the number of observations and methods of statistical data processing. GCRG is more common in long bones, but rare cases of damage to the bones of the facial skeleton, which account for only 2–12 %, have been described. The etiological factors of GCRG are unknown, but genetic predisposition and intraosseous hemorrhages after an injury are the predisposing factors. Despite its benign nature, the process can be locally aggressive. Rapid invasive growth, complex anatomy of the base of the skull in childhood make surgical treatment in this place quite difficult. The clinical symptoms of ethmoid GCRG are nonspecific and depend on the site involved and the degree of local destruction. Distinctive morphological features of this neoplasm are the presence of multinucleated giant cells, cellular fibrous tissue and hemorrhages. Diagnostics of this disease includes endoscopic examination of the nasal cavity and nasopharynx, magnetic resonance and X-ray computed tomography of the skull base, paranasal sinuses with intravenous contrast, radioisotope research methods. We report a case of the development of GCRG in a 6-year-old child, along with the clinical picture, X-ray, scintigraphic and morphological data. The method of choice for the treatment of GCRG was its complete surgical removal.