The incidence of major CNS malformations detected in the neonatal period was calculated on the last consecutive 33969 hospital deliveries and was published in the Bulletin 2003. In this short article we present few notes about the incidence of small and large heads and the possible inversion of their rates in the future. Hydrocephaly is a heterogeneous entity. In this study we considered the diagnosis when the head circumference was enlarged with the presence of ventricular dilatation or with abnormally enlarged ventricles even if the head circumference was not enlarged yet. If no other intracranial malformation like Dandy walker or absent corpus callosum or other extra CNS malformation was found the hydrocephalus was classified as isolated. Cases of hydrocephaly associated with NTD were not considered under hydrocephaly as all cases of acquired hydrocephalus due to intracranial hemorrhage or congenital toxoplasmosis. Colpocephaly was considered when the volume of the frontal horns was nearly normal and there was major dilatation of the occipital horns without absence or evident hypoplasia of corpus callosum and in the absence of NTD or Arnold Chiari malformation. Hydranencephaly is a condition of uncertain origin characterized by an intact skull and absence of cerebral hemisphere. Holoprosencephaly is a malformation in which the prosencephalon has failed to undergo segmentation and cleavage into paired symmetric cerebral hemispheres. Microcephaly was considered in this series when the head circumference was at least 3 standard deviations below the mean for gestational age. Malformations associating CNS anomalies with chromosomal aberration were considered with chromosomal aberrations.