This article investigates the family and child welfare system in Lithuania in terms of social sustainability, with an emphasis on children’s rights. The conceptual framework of Gilbert et al. (2011a) on child welfare was used as the substance of the research, identifying the problem frame, aim and mode of intervention, and parent–state relationship as the main dimensions for analyzing configurations of the child welfare systems. The analysis in this article focuses on how the family and child welfare system is observed in everyday professional practice in Lithuania by linking it with the social sustainability concept. The quantitative research sample comprised 501 respondents from Lithuania, representing different professionals of the family and child welfare system. An online questionnaire was distributed across regional municipal social services departments and to the national service of the State Child Rights Protection and Adoption Service. Explorative factor analysis and multidimensional scaling were used for data analysis. The research demonstrated that family and child welfare dimensions are meaningfully related to the social sustainability concept through the rights of a child such as the child’s best interests, accessibility to services, the right to be heard, protection against violence, child identity, development assurance, and so forth. The research indicates the need for awareness raising, including education and training for professional actors regarding child and family welfare, as an integral part of the concept of social sustainability.