Intradiploic meningioma, which may be classified as a subgroup of intraosseous meningioma, is a rarely encountered disorder. To date, less than 10 cases have been reported. Here, we report a case of fronto-orbito-nasal intradiploic meningioma, A 12-year-old female with exophthalmos and diplopia was operated on for a cranial intradiploic mass lesion. Histopathological evaluation of the specimen confirmed the diagnosis of intradiploic psammomatous meningioma. Her exophthalmos did not change, but the diplopia disappeared. This case is unique in that it is an extensive case of intradiploic meningioma of the orbital roof and frontal base in a child. Intradiploic meningiomas generally are of psammomatous type. Especially tumors adjacent to the orbita cause exophthalmos; cases located on the other side of the calvarium may not cause any symptom or sign other than headache or sometimes a mass on the scalp. Treat ment, as with meningiomas located in the intracranial cavity, is total resection of the lesion. Copyright (C) 2000 S. Karger AG. Basel.