Renal osteodystrophy is a common complication of end-stage renal failure patients. It's most severe osseous complication is characterized by massive thickening of the cranial vault and facial bones, called uremic leontiasis ossea (ULO), with only few cases reported in the literature. A case of a 47-year-old female patient with ULO is presented. Physical examination showed enlargement of the jaws, which hinders proper ventilation and feeding. The computed tomography examination showed marked osseous proliferation in the jaws causing severe bony expansion and loss of normal bony architecture in the skull and the skull base. The most relevant clinical, histopathological and laboratory findings are discussed. The uremic leontiasis ossea causes significant aesthetic and functional changes. Correct diagnosis and management of the factors responsible for the development of bone lesions due to altered bone metabolism are key factors. The maxillofacial surgeon must have the proper knowledge of patient's medical condition and bone maturation status to address an adequate surgical strategy.