Service users subject to section 41 of the Mental Health Act 1983 come under the scrutiny of both the mental health and the criminal justice systems. Much of the sociological literature in this area focuses on the growth of risk-related practices in which risk management is arguably displacing more traditional notions of care. Social workers who are working with service users subject to section 41 are faced with a number of ethical dilemmas. This paper outlines Kantian, utilitarian and virtue ethics and their possible application to work with service users subject to section 41. The ethical dilemmas in applying risk assessment tools are then examined. Finally, the article draws on published research of service user views in order to consider ethical dilemmas further. The author concludes by considering how social workers might apply the ethical principles discussed.