The debate on the ethics of involuntary treatment for Anorexia Nervosa (AN) is dominated by biomedical ethics approaches to the issues. In keeping with the biomedical ethics emphasis on objectively balancing ethical principles, the debate centres on how to respect the autonomy of persons with AN who refuse treatment whilst protecting these persons from harm. Commentators discuss this at a normative ethics level. Thus, the debate does not address the moral relevance of how knowledge is constructed in the practice environment (...) and the impact this has on how professional values are applied during treatment decision making. Social work ethics highlights the need for professionals to account for the authority of professional knowledge and for patients to participate in treatment decisions. However, in the practice environment, questioning medical hegemony and supporting patient participation, empowerment and self-determination (core social work values) is complicated by a lack of treatment efficacy, the high level of risk that patients present to themselves and uncertainty around the autonomy and competence of the patient to refuse treatment. This paper argues that postmodern ethics can support practitioners in managing these issues. In doing so, this paper makes a social work contribution to the debate. (shrink)