A rare case of a 13-year-old boy with ossifying fibroma in the parietal bone is presented, and differential diagnosis from other fibro-osseous tumors such as osteoma and fibrous dysplasia is briefly discussed. X-ray films of the skull showed a round, well-circumscribed osteoplastic lesion with a few radiolucent spots in its interior in the right parietal bone. Tomograms of the lesion revealed a smooth margin with an egg-shell appearance and some delicate streaks. Histological findings of this lesion showed osteoblastic rimming, some infiltration of xanthoma cells and lamellar bony structures. Histological distinction between ossifying fibroma and fibrous dysplasia was emphasized.