Cephalhematoma is a collection of blood beneath the periosteum of the bones in the cranial vault. The treatment strategy of most cephalhematoma is conservative. However, in cases of ossified cephalhematoma causing deformities of skull, surgical management is indicated. From 1996 to 2002, the authors treated three cases of ossified cephalhematoma with the suggested pathogenesis of ossification, which cephalhematoma goes to ossification process, rather than calcification. Surgical treatment, which is bony shaving with a burr on the irregular margin site, was performed in one case in which the thickness of the skull in the bulging area was the same as in the normal area in preoperative computed tomography (CT) scan, and a depression did not exist in the operative field. In two cases in which there was any difference in bony density in the preoperative CT scan and depression after removal of cephalhematoma, the bony cap was remodeled into multiple pieces and the depressed region was reconstructed with a remodeled bone cap as an onlay bone graft. There was no evidence of complications and recurrence, and there was good reconstitution of the skull contour in all cases.