This article applies insights of the contextual theory and therapy, developed by Ivan Boszormenyi-Nagy, to the body of knowledge and practice of social work. Social work and contextual therapy share their focus on justice. In social work, it is mainly elaborated as social justice, placed in the discourse of politics and action. Contextual therapy however, elaborates justice as relational ethics; a fundamental element of human relationships, expressed in an innate tendency to care for each other. According to the contextual theory, evoking this reciprocal care enhances human wellbeing. Therefore, next to the focus on social justice on macro level, this article introduces a focus on relational justice on micro level. Relational justice aims at restoring and enhancing relationships within the family, with those who are relevant for the wellbeing of the family, and with the family’s context. A focus on relational justice encompasses a promising resource for human wellbeing, and a constructive framework for a contextual social work approach. Subsequently, applicable interventions from the contextual therapy, derived from a previously conducted qualitative research on the practice of contextual therapy, are tailored to the social work practice. Conclusively, this article states that justice within family relationships is an important element for successfully realizing of social justice.