The UN Convention on the Rights of the Child (1989) is the first international document covering the rights of the child as a seperate human being,with the obligation of countries to respect the principle of the best interest of the child, which must be followed in all procedures. Considering the principle of the best interests of the child, the paper analyzes adoption as a permanent form of parental care for the child. Although every child has the right to grow up in a biological family, there are various reasons (underage parents, illness, etc.) that make it impossible. In such situations, parental care for that child may be established through an adoption institute. Adoption is a process that requires assessment, preparation, and supervision that will ensure a good decision-making with respect to a particular child and the most appropriate potential adoptive parent. Since it brings about significant changes for the adoptive parents, as well as the child and the environment in which the child is located, professional education and support is needed. Today, there is a growing number of so-called non-traditional families in the form of same-sex partnership, who, in the fight for their rights, among other things, want the right to adopt. In many countries, this right is still in its infancy, as there is considerable controversy and debate about how children growing up in such communities will develop and build their identities. In the context of the Law on Life Partnership same- sex, parental and partnership care of same- sex partners in the Republic of Croatia is analyzed.