The purpose of this essay is to create an understanding of how social workers work to ensure that the best interest of the child is achieved in custody disputes. The essay is based on seven semi-structured interviews with practicing social workers working with family law. The gathered material was analyzed using a thematic analysis method. The results of the study show that working with the best interest of the child in mind, using a child´s perspective, is complex and difficult. One of the reasons why it is difficult is that there is no exact definition of what “the best interest of the child” is and how it should be realised by the social worker since the concept should be assessed and applied individually every single time. All of the respondents states that the investigation is imbued by the wellbeing of them say that ultimately the child´s best interest is not what is valued the most in the investigation. The material shows that all the respondents are aware that the children’s perspective should be prominent during the entirety of the investigation. It is a common goal amongst the respondents to always work with the children’s perspective in mind, to ensure the best interest of the child.