The right to refuse treatment is the most controversial of the rights of mental patients, and usually polarizes the movement for mental health reform between providers of care and external activist reformers. A broad alliance supported earlier struggles for recognition of patients' rights, but most professionals oppose recognizing this most extreme right of treatment refusal. Professional opposition to treatment refusal is not based on a wide extent of actual refusal; rather it derives from a defense against challenges to professional and institutional autonomy, an opposition to legal interference, and a belief that the community as well as the patient must be protected. These three reasons for opposition are examined by reviewing studies of attitudes toward patients' rights, knowledge about patients' rights, and implementation of patients' rights. Finally, the implications of these studies for future directions in the movement for patients' rights are examined.