We report on 4 cases of brain tumors associated with tuberous sclerosis. In each case the tumor was in the region of Monro's foramen and was associated with ventricular dilatation. Computer tomography scans, which were performed in 3 cases, revealed well-circumscribed high-density masses which were markedly enhanced by contrast medium. 3 patients underwent craniotomy. Total extirpation was performed in 2 patients. Both of them are doing well postoperatively. However, 1 patients whose tumor had been partially resected died of recurrence 6 years after surgery. The pathology of three tumors was different in each case: plump cell astrocytoma, hemangioma and astroblastoma.