Objective: Osteolytic lesions of the skull in children have a broad differential diagnosis including congenital, inflammatory and neoplastic lesions. Progressive osteolysis of the skull secondary to head trauma is rare and has been poorly characterized. Methods: The pediatric database at our hospital was screened for children with osteolytic lesions who had a previous mild head injury without fracture or dural tears. We identified 2 children with circumscribed progressive cranial osteolysis after minor head trauma detected by CT and MRI scans. Three additional cases were found in a review of the published literature. Results: Ten children with an osteolytic skull lesion treated between January 1998 and February 2008 were identified in our pediatric database. In 2 children there was evidence of previous mild head injury without a skull fracture. Trauma had occurred 7 and 2 months prior to presentation, respectively. The inner table of the skull was intact in both cases. In 1 case, surgery was performed, and in the other case, a wait-and-see strategy was adopted. Pathological examination in case 1 revealed an organized hemorrhage with focal papillary endothelial hyperplasia. Conclusions: Progressive osteolytic calvarial lesions may occur in both infants and adolescents after mild head injury. They involve either only the diploe and outer table of the skull or both the inner and outer tables. These lesions might be due to intradiploic or subgaleal hematomas triggering an inflammatory process. While surgical resection can be considered to confirm a histopathological diagnosis and to exclude other diagnoses, spontaneous reossification is possible.