Objective — Advocacy in the mental health services field is gaining importance since the traditional role of mental health hospitals is changing, particularly in North America and in Western Europe. This review will define advocacy, its goals and fundamental principles. It will then delineate the skills and strategies needed for any intervention on behalf of a patient or a group of patients. It will also deal with the issues and approaches most frequently raised and used, and finally, with the limits of advocacy. Method — The method used for this review was mainly a recension of the literature concerning advocacy throughout North America and Europe, having in view to see emerging the principal stakes and concerns related to this process. Results — Advocacy has a significant impact patients' awareness of their rights and their capacity to exercise them. It also prevents potential abuse of patients. On the other hand, some patients have an increased opportunity to cease treatment, and this could lead to serious medical consequences. There is also the possibility of retaliation from staff, as a result of being involved with an advocate. The combination of high quality care and effective advocacy is the best guarantee that a mental health patient will get the care he wants and needs with human dignity.