ABSTRACT This article investigates mechanisms through which neuroticism leads to distress in daily life. Neuroticism may lead to distress through exposing people to a greater number of stressful events, through increasing their reactivity to those events, or through a mechanism unrelated to environmental events. This article evaluates the relative importance of these three explanations. Subjects were 339 persons who provided daily reports of minor stressful events and mood for 6 weeks. Exposure and reactivity to these minor stressors explained over 40% of the distress difference between high- and low-neuroticism subjects. Reactivity to stressors accounted for twice as much of the distress difference as exposure to stressors. These results suggest that reactions within stressful situations are more important than situation selection in explaining how neuroticism leads to distress in daily life.