Relationship-based practice has become a dominant theory through which what goes on between social workers and service users is understood. However, the presence of a relationship explains little and much more critical attention needs to be given to the kinds of relationships involved in social work. This paper is based on an ethnographic study of long-term social work that spent 15 months observing practice and organisational life, a key aim of which was to find out how social workers establish and sustain long-term relationships with children and parents in child protection cases. The paper introduces into the social work literature the concept of a ‘holding relationship’, which was present in several of the cases we studied, especially where therapeutic change occurred. It shows in detail how a ‘holding relationship’ involved social workers being reliable, immersing themselves in the service user’s day-to-day existence, getting physically and emotionally close to them, and practicing critically by taking account of power and inequalities and using good authority. The concept of a ‘holding relationship’ draws on psycho-dynamic and sociological theory to provide new ways of thinking that can help make sense of the practical and emotional relating involved in social work and promote the development of such helpful relationships.