The principle of "best interests of the child" derives from the Convention on the Rights of the Child as the most important, fundamental, international document protecting children's rights. The best interest of the child during and after the divorce of parents includes the availability and support of both parents, the right of the child to the relationship and the opinion of the parents, and the co-operation of the parent with important and common decisions on the child, the positive attitude and active encouragement of the child to visit with the other parent and appropriate child protection from partner conflicts. Parental manipulation in highly conflicting divorces is a common case. The interests of the parents overshadow the child's interest. Parents who are first called to protect the best interests of the child are in fact the first violators of the same right. Current findings suggest that divorce alone does not have long-term consequences for the child, that is, much more important than whether the parents are divorcing whether the divorce is characterized by a high degree of conflict. Children's exposure to chronic, open and unresolved conflicts increases the risk of long-term difficulties in children, where manipulative behavior of parents is particularly risky. Assessment of manipulation requires education and the great responsibility of professionals supporting families in divorce. In cases of erroneous assessment, their decisions can support the manipulative behavior of parents and thus endanger the realization of the best interests of the child in the long run.