Historically, the views of lawyers and social workers in the application of socio-legal protection of children in the Czech Republic often fail to understand the best interests of the child (the best interests of the child under the UN Convention on the Rights of the Child). In 90´s we can see in practice the direction of implementation of the basic principles of the Convention into individual decisions of social workers. Emphasizing the principle of proportionality between the various rights of the child should lead to the recognition of the child as the holder of the rights, not as the object of care and protection. However, in the late modern era, we have seen a certain shift. Instead of reflecting on the subjective conviction of the creator of what is best for the child; rather, decisions that consist not of ignorance of the content of these fundamental rights and freedoms, but of determining the values of the decision maker. Therefore, this should lead us to a deeper reflection on how workers in social and legal protection institutions understand the issue of the best interests of the child and to further discuss its implementation. The research part of the article focuses, through qualitative interviews, on uncovering how social workers in child protection in the Czech Republic think about the best interest of the child and their impact on practice, and these results relate to the perspective of lawyers extracted from legal acts, regulations, and judgments.