AIM This paper presents a review of the theoretical and empirical literature addressing patient autonomy and how nurses can support patient autonomy. BACKGROUND Nurse-led, shared care settings provide needs-based care to patients who are encouraged to participate actively in their care. Patient autonomy is a complex ethical concept with many different meanings. As a result, nurses must solve various problems to foster patient autonomy successfully. METHOD Two methods were used to identify literature for the review: (a) a search of the MEDLINE, Embase, CINAHL and Online Contents databases and the keywords 'patient autonomy' in combination with 'nursing', and the Dutch Central Catalogue for material published from 1966 to 2005; (b) ethical and nursing literature was selected on the basis of its identification of positive and negative freedom. We reviewed qualitative empirical research to explore the patients' views of autonomy. FINDINGS Negative freedom emphasizes freedom of action and freedom from interference by others. Positive freedom stresses the idea that people should direct their lives according to their personal convictions and individual reasons and goals. The most prominent theories fitting negative freedom are those defining autonomy as self-governance and self-care. Theories fitting positive freedom are those focusing on autonomy in caring, autonomy as identification, autonomy as communication and autonomy as goal achievement. In the empirical literature, two studies centred on patient autonomy in home care, one in nursing home care and three in hospital settings. To achieve autonomy, patients prefer a mixed approach that combines features of negative and positive freedom. CONCLUSION Nurses cannot rely exclusively on one model of autonomy to foster patient autonomy. Rather, it requires in-depth knowledge of, and interaction with, patients in the context of each particular nursing encounter because people express their autonomy through particular courses of action.