Positive emotional states may promote healthy perceptions, beliefs, and physical well-being itself. To explore potential mechanisms linking pleasant feelings and good health, the authors consider several lines of research, including (a) direct effects of positive affect on physiology, especially the immune system, (b) the information value of emotional experiences, (c) the psychological resources engendered by positive feeling states, (d) the ways in which mood can motivate health-relevant behaviors, and (e) the elicitation of social support. As anticipated by the Greek physician Hippocrates, positive emotions and healthy outcomes may be linked through multiple pathways.