Fibrous dysplasia (FD) is a progressive systemic bone tumour of young and it can be seen on cranial bones. FD is divided into three types according to radiological features. The second most common subtype is polyostotic subtype. With this article, we aimed to review and present clinical features, radiological examination, differential diagnosis and treatment management of a case of solitary monostotic fibrous dysplasia of occipital bone. 15 years old female patient admitted to our hospital for a bump and in the back of his head that she noticed 1 month ago. Her physical and neurological examination was normal. On cranial CT examination we detected a bony defect. Her gadolinium enhanced cranial MRI revealed bony defect along with massive gadolinium enhancement in adjacent tissue. On histopathologic examination; PANCK, CD68, CD1a were found negative and CD45, S-100, Vimentine were found positive. Ki-67 was 4,8%. In conclusion, fibrous dysplasia is a progressive bone disease of the young patients. Despite its resemblance to a benign lesion by not being symptomatic it can progress and cause severe bony defects and skin lesions. Total surgical resection is necessary and sufficient for total treatment.