Fibrous dysplasia, a rare benign condition with an uncertain cause, is characterized by substituting normal medullary bone with abnormal and weak fibrous and osseous tissue. This primary bone disorder is non-neoplastic and involves a deficiency in osteoblastic differentiation and maturation, which begins in the bone’s mesenchymal precursor. A 20-year-old female attended ENT OPD with complaints of headache for 3 years, A diagnostic nasal endoscopy was done which showed no significant abnormalities, and CT PNS was done which showed Extensive sclerotic bony expansion with a ground glass appearance involving the clivus, right greater wing of sphenoid, pterygoid processes - Likely fibrous dysplasia since she had no other signs or symptoms, she was kept under observation.