A total of 21 neonates with intraventricular hemorrhage (IVH) were studied; 12 (57.1%) survived, and 7 (58.3%) of these 12 cases suffered from hydrocephalus. Hydrocephalus occurred only in patients with IVH of grades III and IV on Papile's classification, and its occurrence rate was 87.5% as the sum total for the two groups. Destructive hydrocephalus (DHC) occurred in 5 cases of grade III and grade IV, and its occurrence rate was 62.5% as the sum total for the two groups. It could be conjectured that the prognosis of the IVH depends upon the extent of the primary hemorrhagic lesions. However, in cases with DHC, the resistance of the cerebral parenchyma to the hydrodynamic force is decreased, so that secondary cerebral destruction yielding rapid and intense ventricular dilatation, which is responsible for the development of neurological disorders, might occur more easily than in cases with IVH of grades III and IV, and to the secondary parenchymal destruction that may arise in association with hydrocephalus. It is essential that a shunt operation should be performed as soon as possible after the diagnosis of DHC has been established so as to allow repair of the primary lesion and to minimize the secondary brain damage.