Parental alienation during divorce is a serious problem affecting about 30% of family with divorced parents. Alienation happens when one parent is programing the child against the other parent and in most cases, against his relatives. The parent will program the child using numerous of destructive strategies such as isolation, vilification of the targed parent, intimidation, lying, and manipulation in a variety of ways. That parent is so occupied with his own emotions and needs that he can't seperate his role as a parent and his role as a formal husband/wife, he will do everything to get custody of children, even if that meens a false allegation of child abuse, he belives that the other parent is so bad that should disappear from the child's life and he can't see how damaging is this to a child. The dameged is significant. Some of the consequences are the of a parent and relatives, distorted perception of reality, low self-esteem, anxiety, depression and the child learns that destructive behaviors are acceptable so he transferr them to his future relationships. Alienation is a serious problem and it is important to take an active approach to prevent its frightening effects. This article will describe in detail the problem of alienation during divorce , it's legal aspect, role of relevant institutions and examples of court rulings in the Croatia and in several other countries.