Supervision is a core component of professional support and development in social work. In many settings, and perhaps particularly in children’s services, it is valued as crucial in safe decision-making, practice reflection, professional development and staff support. Research has demonstrated that supervision and staff support also contribute to social worker retention in child welfare services. Drawing on data gathered in a 15-month ethnographic, longitudinal study of child protection work that included observations of supervision, we were able to observe the impact of supportive supervisory relationships on social workers’ decision-making about staying in their current workplace. This article presents a single case that demonstrates the potential impact of effective relationship-based supervision on retention and calls for a more humane approach to social work supervision against dominant managerial themes that have increasingly burdened the profession.