For many decades, the stress process was described primarily in terms of negative emotions. However, robust evidence that positive emotions co-occurred with negative emotions during intensely stressful situations suggested the need to consider the possible roles of positive emotions in the stress process. About 10 years ago, these possibilities were incorporated into a revision of stress and coping theory (Folkman, 1997). This article summarizes the research reported during the intervening 10 years that pertains to the revised model. Evidence has accumulated regarding the co-occurrence of positive and negative emotions during stressful periods; the restorative function of positive emotions with respect to physiological, psychological, and social coping resources; and the kinds of coping processes that generate positive emotions including benefit finding and reminding, adaptive goal processes, reordering priorities, and infusing ordinary events with positive meaning. Overall, the evidence supports the propositions set forth in the revised model. Contrary to earlier tendencies to dismiss positive emotions, the evidence indicates they have important functions in the stress process and are related to coping processes that are distinct from those that regulate distress. Including positive emotions in future studies will help address an imbalance between research and clinical practice due to decades of nearly exclusive concern with the negative emotions.