The study population included 193 patients with prenatally diagnosed (fetal) hydrocephalus and 181 with postnatally (12 or less than 12 months after birth) diagnosed (infantile) hydrocephalus identified by a nationwide questionnaire survey of congenital hydrocephalus performed in 2000. Of 180 patients with fetal, 101 (56.1%) were diagnosed before week 32 of gestation and 18 (10%) were diagnosed week 37 and later of gestation. In patients with fetal hydrocephalus, US was used in more than 80% of the cases, whereas in patients with infantile hydrocephalus, CT was used in more than half of the cases. For diagnosis of fetal hydrocephalus, either US or MRI had become dominantly utilized and CT had gone out of use in 1996-2000. The adoption ratio of cesarean delivery to transvaginal delivery was around 7 to 3 in patients with fetal hydrocephalus, and 2 to 7 in patients with infantile hydrocephalus, respectively, with significant difference between fetal hydrocephalus and infantile hydrocephalus groups (p < 0.001). Clinical outcomes in patients with fetal hydrocephalus was better in those delivered transvaginally than in those by cesarean delivery, although without no statistical significance (p = 0.124) and those in patients with infantile hydrocephalus showed almost no difference between transvaginal and cesarean delivery groups. There was a tendency for the Apgar score at 5 min to be lower in smaller birth weight infants with a body weight of less than 2000g. This score could be useful as an index for predicting immediate postnatal death in patients with fetal hydrocephalus.