The rare cases of subgaleal hematoma in childhood reported previously have all been related to head trauma. A case of apparently spontaneous subgaleal hematoma is reported which was associated with a qualitative platelet defect and not with trauma. Subgaleal hematoma must be differentiated from subgaleal infection and air from frontal sinusitis with bony erosion, and from an encephalocele or tumor erosion through the skull. Computed cranial tomography is useful in that differentiation. Most cases have been managed conservatively, but subgaleal tap may be indicated if there is severe headache or potential scalp necrosis.