Secondary, paraventricular and, less frequently, primary tumors of the lateral and third ventricles usually of supratentorial localization prevailed among congenital tumors of the brain. They impair the drainage of cerebrospinal fluid and cause internal hydrocephalus. The clinical picture of congenital cerebral tumors is characterized by a manifest hypertensive-hydrocephalic syndrome and a severe general condition. The neurological symptomatics, the EEG and the Echo-EG usually yielded exact information on internal hydrocephalus but rarely helped in determining the localization and character of the tumor. Pneumoventriculography, angiography, computer tomography, and radioisotope diagnosis were methods which provided the most information. Pneumoventriculography, however, causes many complications and the method of isotope diagnosis and computer tomography is therefore preferable because it is sparing and safe for the use in children of the first year of life.