A case of intrasellar meningioma is reported. A 49-year-old woman was admitted to our hospital on July 22, 1985, complaining of reduced visual acuity and visual field defect. Visual acuity was 0.6 in the right eye and 0.1 in the left eye. Visual field examination revealed upper temporal quadrantanopsia on the right side and incomplete temporal hemianopsia on the left side. Ocular fundi were normal. X-ray films of the skull showed a balloon-shaped sella turcica with "double floor". CT scan showed a isodense mass with central low density occupying the intrasellar and suprasellar region. After administration of contrast medium, almost homogenous enhancement was noted. Bilateral carotid angiographies demonstrated that horizontal portion of the right anterior cerebral artery was raised. No tumor blush was evident. Endocrinologic function tests confirmed a complete deficit of the anterior lobe hormones except for elevated serum prolactin level of 110 ng/ml. She showed no galactorrhea. On August 6, 1985, the sella turcica was reached via the transsphenoidal rhinoseptal approach. The sella floor and dura matter were intact. The grey, soft and necrotic tumor tissue was encountered and bleeding was controllable. The tumor extending to suprasellar region was firm in consistency. Pathologically, the tumor was a typical meningothelial meningioma. Postoperatively, visual field defect improved and visual acuity was recovered on the right side immediately. Postoperative CT scan showed a thin residual enhanced lesion, which was the attachment of the tumor. It seemed to be the elevated diaphragma sellae. Clinical observation, radiological and endocrinological findings of intrasellar meningioma are similar to that of non-functioning pituitary adenoma.(ABSTRACT TRUNCATED AT 250 WORDS)