This book shows the potential of posthuman thinking for rethinking health care, experiences, subjects and interventions. It explores a range of posthuman dilemmas across diverse health issues as contributors grapple with the ethical, ontological and epistemological relations of knowing and doing health.The volume problematizes the rational, agentic individual as the key driver of health-related action and experience. Contributors move beyond long-held humanist assumptions about health, illness, and well-being and attune – theoretically and methodologically - to the entangled relations or ecologies that instantiate realities. They reimagine how care practices and healthcare experiences materialise through human-non-human relationality as biosocial environments. Chapters explore and articulate the agency of more-than-human entities in health-related processes to shed new light on health interventions, evaluations, and health policy. Taken together, the book highlights that although posthumanism enables health sociologists to progress particular agendas, it is essential to further problematise the posthuman decentring of the human by bringing sustained attention to bear on the ethical and political implications of this approach to knowledge-making in health. This field-defining collection consolidates and builds momentum in the burgeoning area of posthuman thinking in health.It will appeal to scholars and researchers seeking to understand health as a relational achievement better. This book was originally published as a special issue of Health Sociology Review.