Self-care as both treatment and prevention is assuming new importance for several reasons: chronic illness, which calls for self-care is becoming a more serious global problem; illnesses that are related to unhealthy behavior are more common; medical care is becoming more participative because of increased individualism; the costs of care make it necessary for more care to be assumed by patients; and new technology expands what people can do for themselves. Self-care is relevant to the enhancement of health, the prevention of illness; the management of disease, particularly chronic illnesses; and rehabilitation to reduce disability. Barriers to self-care include mental attitudes of depression and denial, addictions, cultural factors, low intelligence and illiteracy, and family conflict. Self-care is enhanced by a sustaining relationship with a health professional, trustworthy information, patient education that is culturally sensitive, technological aids, financial and other positive incentives, and peer group support. Self-care is a growing dimension of health care that needs and deserves further research and innovation.