Leontiasis ossea (lion’s face) is a specific form of hyperostosis of the bones of the cranial and facial skull, which often leads to disfigurement. The term leontiasis is a collective concept. Changes are most often caused by fibrous dysplasia, but can be observed in Peget’s disease, Recklinghausen’s disease and renal osteodystrophy (Siglyker syndrome).The article presents comparative clinic-anatomical and laboratory parameters that are important in identifying the cause of leontiasis ossea. It also presents data on the nature of radiographic changes in the bones of the skull in the above diseases, approaches to differential radiographic diagnostics and the choice of further diagnostic tactics.The above observation emphasizes the importance of radiographic examination, especially in cases of primary radiodiagnostics, assessment of the nature of changes in the bones of the skull in patients with leontiasis ossea.