Professional autonomy is often described as a claim of professionals that has to serve primarily their own interests. However, it can also be seen as an element of a professional ideal that can function as a standard for professional, i.e. medical practice. This normative understanding of the medical profession and professional autonomy faces three threats today. 1) Internal erosion of professional autonomy due to a lack of internal quality control by the medical profession; 2) the increasing upward pressure on health care expenses that calls for a health care policy that could imply limitations for the professional autonomy of physicians; 3) a distorted understanding of the profession as being based on a formal type of knowledge and related technology, in which other normative dimensions of medical practice are neglected and which frustrates meaningful communication between physicians and patients. To answer these threats a normative structure analysis of medical practice is presented, that indicates which principles and norms are constitutive for medical practice. It is concluded that professional autonomy, normatively understood, should be maintained to avoid the lure of the technological imperative and to protect patients against third parties' pressure to undertreatment. However, this professional autonomy can only be maintained if members of the profession subject their activities and decisions to a critical evaluation by other members of the profession and by patients and if they continue to critically reflect on the values that regulate today's medicine.