A 2-month-old female infant had had a parietal mass since birth. Neuroimaging revealed a lipoma under the splenium of the corpus callosum that was connected to the subcutaneous lipoma via a bone defect in the cranium bifidum of the parietal region. At the age of 5 months, partial resection of only the extracranial mass was carried out. The histological diagnosis was lipoma. She grew up normally without neurological disorders during follow up for 12 years after the surgery. In the present case, the intracranial lipoma was associated with the cranium bifidum, and dysraphism was possibly involved in the pathogenesis. Resection of only the extracranial subcutaneous tumor can be performed for cosmetic reasons.