Hydrocephalus is one of the most frequent neurological and neurosurgical diseases in children that has a negative impact on the further mental development of children. However, there is a clear lack of clinical-psychological researches of features of mental development of children with hydrocephalus. The purposes of our study is to research neuropsychological and intellectual peculiarities of pre-schoolers, that has occlusive hydrocephalus or hydrocephalus syndrome in anamnesis (in our case we have studied children with dilatation of cerebral ventricles). We have investigated 45 children, among them 23 children had occlusive hydrocephaly in anamnesis and shunting of the brain and 22 children, whose dilatation of brain was noted in the baby age. In order to compare the data, received in the experimental sample, we have researched 23 normally developing children as well. The level of the intellectual abilities development, as well as the qualitative features of the development of cognitive functions using a G. French methodology PTI in the adaptation of N. A. Shumskaya and a neuropsychological features with help of six scales of neuropsychological battery was researched. Data processing was performed using the methods of mathematical statistics (variance and correlation analysis). The children, that had hydrocephaly in anamnesis and neurosurgical operation, had development delay of intellectual abilities related to wrong conclusions (subtest of perceptivity) difficulties in concentration of attention (subtest of similarity) and unlike normally developing children to ignorance of numbers (subtest of arithmetic). The children, having occlusive hydrocephaly in anamnesis, experience a difficulty with acoustic gnosis and speech, vividly expressed development delay of practical function. At the same time, there were no disturbance or delay of psychic development of children, that had hydrocephalus syndrome in anamnesis.