Optimism is expecting good things to occur in your life. Such positive expectations are associated with higher levels of subjective well-being, better physical health, and a higher quality and quantity of social relationships. The benefits of optimism are partially attributable to the manner in which optimists and pessimists cope with adversity. Optimists tend to cope with adversity actively, attempting to solve problems when they can, accepting problems that they cannot resolve, and focusing on the positive aspects of their experiences. In addition to coping with adversity better, optimists also appear to engage in proactive efforts to prevent problems in the future, including taking actions to minimize various kinds of health risks. Although previous research has clearly demonstrated the benefits of optimism across a wide array of outcomes, there remains several unresolved issues concerning the effects of optimism and how optimism should be conceptualized, which are discussed.