This article explores the implications that dispositional optimism holds for physical well-being. Research is reviewed that links optimism to a number of different positive health-relevant outcomes, ranging from the development of physical symptoms to recovery from coronary artery bypass surgery. Additional findings are described which suggest that these beneficial effects are partly due to differences between optimists and pessimists in the strategies that they use to cope with stress. A number of other potential mediators are also discussed, including some that are physiologic in nature. The article closes with a discussion of the relationships between our own theoretical account of the effects of optimism and several other conceptual approaches.