Research suggests that one of the principal reasons patients are attracted to alternative medicine is that they find many of these therapies more congruent with their philosophical orientation toward health. Many mind-body approaches, which are some of the most frequently used classifications of complementary and alternative therapies, grow out of research demonstrating the important role of psychological factors in treating and preventing illness. This article reviews research on one such factor--control--and its importance in health. Studies demonstrating the following are highlighted: (1) illness frequently results in feelings of loss of control; (2) gaining a sense of control can help patients to cope with illness; (3) whereas control may influence physiological function and health outcomes, the amount of active control we can exercise over physical functioning and health is limited; and (4) it is important to match control strategies to patient control styles and preferences. The implications of mind-body studies are also discussed.