Negative affective styles such as anxiety, depression, and hostility have long been accepted as predictors of increased risk for illness and mortality. In contrast, positive affective styles have been relatively ignored in the health literature. Here we highlight consistent patterns of research associating trait positive affect (PA) and physical health. The evidence we review suggests an association of trait PA and lower morbidity and decreased symptoms and pain. PA is also associated with increased longevity among community-dwelling elderly. The association of PA and survival among those with serious illness is less clear and suggests the possibility that PA may be harmful in some situations. We conclude by raising conceptual and methodological reservations about this literature and suggesting directions for future research.