The biomedical ethical principles of autonomy, beneficence, non-maleficence, and justice are well established, though they have been challenged by feminist and nursing ethics. Decision-making in practice requires a balance of not only ethical principles, but also legal and professional frameworks, alongside patient and family wishes. Cancer clinical trials raise ethical issues around the balance between risk and potential benefits to patients, and they may need support making the right decision about whether to participate. The rising cost of cancer drug treatments has raised difficult questions about which drugs should be authorized for use within the United Kingdom (UK)'s National Health Service. End-of-life care raises particularly challenging ethical issues. Mental capacity or competence is defined in law in the UK, and treatment decisions may be made on behalf of patients if they are assessed and found to lack capacity. However, patients and families are encouraged to make advance statements and decisions about treatment in the event of losing capacity. Decisions on whether to give, withdraw, or withhold treatment, artificial hydration and nutrition, and cardiopulmonary resuscitation (CPR) are sensitive, and should be based on assessment, consultation with family, and consideration of ethical, legal, and professional principles. Euthanasia and physician-assisted suicide (assisted dying) are highly contentious issues internationally and illegal in most countries. Some countries allow them under certain circumstances. In response to a patient asking about assisted dying, the nurse should listen to their concerns, be prepared to talk about the process of dying, and support them to establish their priorities.