A series of 9 patients having a tuberous sclerosis associated to a midline ventricular tumour is reported. Microscopically, the presence of giant cells within the lesion is a major characteristic of the disease. The origin of these subependymal giant cells tumours is questionable since astrocytic, neuronal and ependymal features have been noted by several authors providing various denominations. In the literature and in our series as well, the intra-ventricular tumour presented as the initial manifestation of the disease in most of cases, usually with increased intra-cranial pressure symptoms. On CT, the tumour arises in the area of the foramen of Monro and enhances after contrast injection while the other intracranial anomalies of the disease do not enhance. In 8 patients, a direct transcortical transventricular approach was used. 1 patient was treated by shunt only. The results were evaluated according to the degree of the preoperative neuropsychological impairement: there were 3 deaths, 3 "excellent", 2 "fair" and 1 "poor" results. The problem of the surgical indication raises mainly in patients in whom the diagnosis of the tuberous sclerosis is ascertained prior to the diagnosis of the tumour. Since acute C.S.F. blockage or intra-ventricular bleeding may occur during "conservative" treatment, direct approach seems preferable.