Whether or not to allow socialisation between parents and children in out-of-home care presents a difficult ethical challenge for those social work professionals who need to make an assessment about what to do. In this as well as in other contexts, it is widely assumed that the principle of the best interest of the child (BIC) is both the legal and moral standard for decision-making for children. Yet, from a moral philosophical perspective it is not entirely clear how this principle should be understood, and in the applied ethics literature it has been suggested that BIC should be rejected. In this paper, we defend BIC as the moral standard for ethical decision-making concerning children. We offer an interpretation of BIC that is both plausible from a moral philosophical point of view and that may offer practical guidance for those assessing whether it is morally defensible to restrict social contact between parents and children placed in out-of-home care. Based on our interpretation of BIC, we develop a tentative step-by-step procedure that may help guide social workers and relevant decision-makers when assessing moral reasons for whether to allow or restrict the right to socialisation between parents and children in out-of-home-care.