Ossified cephalhematoma is a rare clinical entity. Even though cephalhematoma is frequently encountered, ossified cephalhematoma occurs only sporadically. We report a 13-week-old boy who was admitted to neurosurgery clinic with deformity of the skull. A plain skull radiograph showed radiolucent areas in the right parietal region. CT scan of the head showed thickened right parietal bone and a low-density lesion between bony layers. 3D CT of the skull showed bony protrusion of the right parietal bone. A cosmetic surgical procedure was performed for the patient, and biopsy of the bony lesion confirmed ossified cephalhematoma. We discuss diagnosis, pathogenesis, and treatment of ossified cephalhematoma.