The notion of “unaccompanied and separated children” was introduced by the UN Convention on the rights of the child. It is widely used by both international human rights community and governmental bodies of various countries in regulation of treatment of the specific vulnerable group of children. The notion, which initially aimed to address specific needs of children-refugees, gradually evaluated and presently refers to children outside of country of their origin who are not being cared for by a responsible adult or who are with family members that are not their primary caregivers, including illegal migrants. Certain scope of rights and guarantees is attributed to the notion to address their needs that should be determined using the best interests of the child principle. Russia does not use the notion developed on the international level in the national law in its human rights meaning. It was literary translated and adjusted to national perceptions (redefined). The content of the term used to define the group in Russia “children deprived of a parental care” (deti, ostavshiyesya bez roditelskogo popecheniya) is similar but not equal. It allows to strip children of the guarantees attributed to the notion “unaccompanied and separated children” by the international treaty and to consider unaccompanied and separated children within the contexts of “violation by parents of their parental rights” and “migration”. The change of the focus brings along a perversion of the understanding of the best interests of these children and measures the state is obliged to undertake to protect them. Moreover, it puts all the blame regarding the situation of children on their parents, leaving the state a secondary role.