Based on in-depth qualitative interviews, this article explores the experiences of vulnerability for nineteen children and families Social Workers in England and discusses how this emotional state manifests and impacts upon practice. As this study shows, workers frequently harbour personal vulnerabilities that can motivate them in their work and act as an enabler within relationships with service users; these same feelings can also provoke a sense of threat and discomfort, resulting in self-doubt and reduced confidence. Whether carried from the past or housed in the present, feelings of vulnerability often rise to the surface when provoked by routine encounters with clients and the knotty issues that surround them; what is valued by Social Workers encountering such feelings is a sense of validation and recognition. In taking an explicit focus on practitioner vulnerability, this article adds an original contribution to the literature concerning the emotional world of Social Workers. It reveals vulnerability to be an important component of identity and a driver for practice, which needs to be given greater consideration in social work training and employment, arguing that enhanced attention to worker histories, emotional challenges and self-care are not only necessary but also essential for practitioner and client well-being.