Cystic meningioma represent a rare entity, accounting 1.7 to 11.7% from the total intracranial meningiomas. We present a 41 years old patients' case who suffered of an progressive bilateral visual acuity decreasing, more pronounced on the right side. The clinical examination revealed a severe reduction of vision, represented by difficulties in light perception on the right side. The MRI and CT scan showed an expansive, multi-lobular, fronto temporal process on the right side (87/58/63 mm), presenting a liquid signal, different from intra-cerebro-spinal fluid, without contrast enhancement at the level of the septae. The patient is operated on, the total resection of an polycystic and spongious tumour being accomplished together with the aspiration of the liquid from the giant peritumoral cyst. The postoperative evolution was favourable. The anatomo-pathological result: meningothelial meningioma. Several classifications, the etiology of intra and peritumoral cysts formation are discussed together with the therapeutical possibilities.