Inequalities in health and well-being are wide and widening and reflect the disadvantaged circumstances in which many people live. Users of personal social services in many cases already experience disadvantaged health and well-being. Social work has established experience of working with marginalised groups, and may play a role in promoting individual and community health and well-being. The value base for social work includes a focus on social justice, which may directly impact on the social determinants of health. Using four examples of social interventions across the life span, this paper considers the role that social work can play in improving the health and well-being of disadvantaged people across the life course, and the implications of this for evidence based social work practice and education.