In the face of growing social, economic, political and demographic challenges, many European welfare states have been confronted with barriers in realising the social rights of certain groups of citizens. This phenomenon has often been referred to as ‘the non-take up of social rights’. Considering the core mandate and key principles of social work as a practice-based profession and academic discipline, we argue that social work should have a key role in knowledge and practice development on understanding and combating the non-take up of social rights. Our integrative contextual literature review, nonetheless, demonstrates that there is a tangible scarcity of theoretically and empirically grounded social work research that generates fruitful and in-depth insights into the socially unjust situations and complex dynamics behind these processes of non-take up. This article therefore aims to identify and discuss the key knowledge gaps in the existing body of research on non-take up. As a result, we address critical foci for a future empirical social work research agenda to munition social work practice development that strongly accentuates the substantial realisation of social rights and accordingly contributes to social justice.