Patient/client advocacy has been claimed as a new role for the professional nurse. This paper presents a critical review of the literature on advocacy in nursing. After briefly outlining the conditions which may have instigated the need for patient advocacy, meanings and models of advocacy are discussed. It is argued that although there are many examples of the advocacy role in health care, models proposed for the nurse as advocate are indeterminate which leads to multiple interpretations and lack of clarity in operationalizing advocacy. Much of the literature focuses on justification arguments for claiming the advocacy role. Key themes are outlined and include: patient advocacy as a traditional role, nurses are in the best position in the health care team, nurses have the knowledge to advocate and finally nurses and patients can be partners in advocacy. However, critical examination reveals many counter-arguments to the above claims and finally concludes that advocacy is a potentially risky role to adopt. It is argued that support systems are inadequate except in low-risk situations and ultimately acts of advocacy remain a moral choice for the individual nurse. Finally the need to conduct research into the interpretation of the patient advocate role by nurses in the United Kingdom is highlighted.