The aim of this study was to understand which factors that lay the foundation for social workers’ custody investigations and the judges’ decisions in custody disputes. Additionally, it was to examine the social workers’ and the judges’ views on children’s’ rights in this process. The study was based on qualitative research where six semi-structured interviews were conducted. Four social workers and two judges working with custody- investigations, and disputes were interviewed. The analysis consists of two key concepts: the concept of discretion and child sociology. The result shows that judges and social workers experience difficulties with interpreting the best interest of the child, that there are different perceptions about when lone and joint custody should be considered and how to best design the rights of access. A common consensus among the interviewees with regards to the best interest of the child, is that each situation requires an individual interpretation while considering necessary safety aspects. Social workers’ statements tend to dominate how the best interests of a child is defined in a judge’s decision. Both professions find ways to accommodate the best interests of the child, even though it does not always turn out ideal. There is a strong believe that the child’s voice is governing the decision, even though our study shows that it is not always considered in the custody investigations nor in court.