A case of an aneurysmal bone cyst of the frontal bone is presented. This lesion is rare in the calvaria. It is a benign condition, and may extend intracranially. Total surgical removal is recommended whenever possible either in one stage or in multiple stages. The operation is comparatively easier in the calvaria than it is in the vertebral column or the long bones, where no more than thorough curettage is usually possible. The fact that this is a definite, readily recognizable pathological entity is stressed. Prognosis is excellent and total removal will effect a cure.